Abstract Testnet
    /

    Contract Diff Checker

    Contract Name:
    JobaSoulBound

    Contract Source Code:

    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.4;
    
    import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
    import "@openzeppelin/contracts/access/Ownable.sol";
    import "@openzeppelin/contracts/utils/Counters.sol";
    import "@openzeppelin/contracts/security/Pausable.sol";
    import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
    
    interface JobaGenesisSoulBoundToken {
        function minted(address addr) external view returns (bool);
    }
    
    contract JobaSoulBound is
        ERC721,
        ERC721URIStorage,
        Ownable,
        Pausable,
        ReentrancyGuard
    {
        using Counters for Counters.Counter;
        Counters.Counter private _tokenIdCounter;
    
        JobaGenesisSoulBoundToken internal GenesisSBT;
    
        // Maximum number of tokens in the genesis collection
        uint256 internal MAX_SUPPLY = 10000;
    
        // Number of tokens minted from the genesis collection
        uint64 public TOTAL_MINTED;
    
        // Mapping to track minted addresses
        mapping(address => bool) public minted;
    
        // mapping address to token ID
        mapping(address => uint256) internal _tokenIdOf;
    
        //base token uri
        string public baseURI;
    
        // Contract URI
        string internal _contractURI;
    
        // Token base fee
        uint256 public fee = 0.002 ether;
    
        bool public isFreeMintActive = false;
    
        address public treasury;
    
        // Event to notify when a profile is updated
        event ProfileUpdated(uint256 indexed tokenId, string newProfileDataURI);
    
        // Event to notify when a token is burned
        event TokenBurned(uint256 indexed tokenId);
    
        // Event set base token URI
        event BaseTokenURI(string baseURI);
    
        // Event for withdrawing funds
        event Withdrawal(address treasury, uint256 amount);
    
        // Event to update treasury address
        event UpdateTreasury(address newTreasury);
    
        // event to notify when token is minted
        event TokenMinted(address indexed addr, string tokenURI, uint256 tokenId);
    
        // event to notify when token has passed a 80% minted
        event MintingCrossedThreshold();
    
        constructor() ERC721("Joba SoulBound Token", "JSBT") {
            baseURI = "https://sbt.joba.network/ipfs/";
            _contractURI = "";
            address genesisSBT = address(
                0xC2E5C667cf7B715306C3C77f10FE8d3857a4eF19
            );
            treasury = address(0x0A524aB6005E83e4cb09ac333DB357E823365931);
            GenesisSBT = JobaGenesisSoulBoundToken(genesisSBT);
        }
    
        /**
         * @param uri The base URI to be set.
         */
        function setBaseURI(string memory uri) public onlyOwner {
            baseURI = uri;
    
            emit BaseTokenURI(uri);
        }
    
        function setContractURI(string memory uri) public onlyOwner {
            _contractURI = uri;
        }
    
        function contractURI() public view returns (string memory) {
            return _contractURI;
        }
    
        function mint(
            string memory profileTokenURI
        ) public payable whenNotPaused returns (uint256 newTokenId) {
            validateMint(msg.sender, profileTokenURI);
    
            if (msg.sender != owner() && isFreeMintActive == false) {
                require(msg.value >= fee, "SBT: mint value incorrect");
            }
    
            _tokenIdCounter.increment();
            uint256 tokenId = _tokenIdCounter.current();
    
            if (tokenId == ((MAX_SUPPLY * 80) / 100)) {
                emit MintingCrossedThreshold();
            }
    
            _safeMint(msg.sender, tokenId);
            _setTokenURI(tokenId, profileTokenURI);
    
            TOTAL_MINTED++;
            minted[msg.sender] = true;
            _tokenIdOf[msg.sender] = tokenId;
    
            emit TokenMinted(msg.sender, profileTokenURI, tokenId);
    
            return tokenId;
        }
    
        function safeMint(
            address to,
            string memory profileTokenURI
        ) public onlyOwner whenNotPaused returns (uint256 newTokenId) {
            validateMint(to, profileTokenURI);
    
            _tokenIdCounter.increment();
            uint256 tokenId = _tokenIdCounter.current();
    
            if (tokenId == ((MAX_SUPPLY * 80) / 100)) {
                emit MintingCrossedThreshold();
            }
    
            _safeMint(to, tokenId);
            _setTokenURI(tokenId, profileTokenURI);
    
            TOTAL_MINTED++;
            minted[to] = true;
            _tokenIdOf[to] = tokenId;
    
            emit TokenMinted(to, profileTokenURI, tokenId);
    
            return tokenId;
        }
    
        /**
         * @dev Allows the owner of the token or the contract owner to update the tokenURI.
         * @param tokenId The ID of the token.
         * @param newTokenURI The new token URI to be set.
         */
        function updateTokenURI(
            uint256 tokenId,
            string memory newTokenURI
        ) public whenNotPaused {
            require(
                _exists(tokenId),
                "ERC721URIStorage: URI set of nonexistent token"
            );
            require(
                ownerOf(tokenId) == msg.sender || msg.sender == owner(),
                "SBT: caller is not token owner nor contract owner"
            );
    
            _setTokenURI(tokenId, newTokenURI);
    
            emit ProfileUpdated(tokenId, newTokenURI);
        }
    
        /**
         *
         * @param addr The address to check token minted to the address
         * @return tokenId The token ID minted to the address
         */
    
        function tokenIdOf(address addr) public view returns (uint256 tokenId) {
            require(minted[addr], "Address has not minted a token");
            return _tokenIdOf[addr];
        }
    
        /**
         * @dev Burns a token, removing it from the blockchain - the token owner or contract owner can burn a token.
         * @param tokenId The ID of the token to be burned.
         */
        function burn(uint256 tokenId) public whenNotPaused {
            require(_exists(tokenId), "ERC721: invalid token ID");
    
            address tokenOwner = ownerOf(tokenId);
    
            require(
                tokenOwner == msg.sender || msg.sender == owner(),
                "SBT: caller is not token owner nor contract owner"
            );
    
            // Burn the token
            _burn(tokenId);
    
            // Remove mapping of the address that minted the token
            delete _tokenIdOf[tokenOwner];
    
            // Emit the burn event
            emit TokenBurned(tokenId);
        }
    
        /**
         * @dev Total supply of tokens.
         */
    
        function totalSupply() public view returns (uint256) {
            return MAX_SUPPLY;
        }
    
        function setTotalSupply(uint64 newTotalSupply) public onlyOwner {
            MAX_SUPPLY = newTotalSupply;
        }
    
        function setFreeMintActive(bool active) public onlyOwner {
            isFreeMintActive = active;
        }
    
        function pause() public onlyOwner {
            _pause();
        }
    
        function unpause() public onlyOwner {
            _unpause();
        }
    
        function setTokenFee(uint256 newFee) public onlyOwner {
            fee = newFee;
        }
    
        function setTreasury(address newTreasury) public onlyOwner nonReentrant {
            // cannot be zero address
            require(newTreasury != address(0), "SBT: Invalid treasury address");
            treasury = newTreasury;
            emit UpdateTreasury(newTreasury);
        }
    
        function withdraw() public payable onlyOwner nonReentrant {
            require(address(this).balance > 0, "SBT: Insufficient balance");
            uint256 balance = address(this).balance;
    
            (bool success, ) = payable(treasury).call{value: address(this).balance}(
                ""
            );
    
            require(success, "SBT: Withdrawal failed");
            emit Withdrawal(treasury, balance);
        }
    
        function setGenesisSBT(address newGenesisSBT) public onlyOwner {
            GenesisSBT = JobaGenesisSoulBoundToken(newGenesisSBT);
        }
    
        // Override tokenURI to use the one from ERC721URIStorage
        function tokenURI(
            uint256 tokenId
        ) public view override(ERC721, ERC721URIStorage) returns (string memory) {
            return super.tokenURI(tokenId);
        }
    
        function isMaxSupplyMinted() public view returns (bool) {
            return TOTAL_MINTED >= MAX_SUPPLY;
        }
    
        // Override the ERC721 transfer functions to prevent transferring
        function _beforeTokenTransfer(
            address from,
            address to,
            uint256 tokenId,
            uint256 batchSize
        ) internal override(ERC721) {
            // Allow operations where:
            // - Minting (from == address(0))
            // - Burning (to == address(0))
            // - Updating or other internal operations (from == to)
            if (from != address(0) && to != address(0) && from != to) {
                revert("SBT: Soul Bound Tokens are non-transferable");
            }
    
            super._beforeTokenTransfer(from, to, tokenId, batchSize);
        }
    
        // Override the _burn function from ERC721URIStorage
        function _burn(
            uint256 tokenId
        ) internal override(ERC721, ERC721URIStorage) {
            super._burn(tokenId);
        }
    
        // Override supportsInterface to include both ERC721 and ERC721URIStorage
        function supportsInterface(
            bytes4 interfaceId
        ) public view override(ERC721, ERC721URIStorage) returns (bool) {
            return super.supportsInterface(interfaceId);
        }
    
        function validateMint(
            address recipient,
            string memory profileTokenURI
        ) internal view {
            // Check if address has minted the genesis SBT token and do not allow minting if address has minted;
            require(
                !GenesisSBT.minted(recipient),
                "SBT: address already minted Genesis SBT"
            );
            // Check if the address has already minted a token
            require(!minted[recipient], "SBT: Address already minted");
            require(TOTAL_MINTED < MAX_SUPPLY, "SBT: collection cap reached");
            require(bytes(profileTokenURI).length > 0, "SBT: Token URI is empty");
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)
    
    pragma solidity ^0.8.0;
    
    import "../utils/Context.sol";
    
    /**
     * @dev Contract module which allows children to implement an emergency stop
     * mechanism that can be triggered by an authorized account.
     *
     * This module is used through inheritance. It will make available the
     * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
     * the functions of your contract. Note that they will not be pausable by
     * simply including this module, only once the modifiers are put in place.
     */
    abstract contract Pausable is Context {
        /**
         * @dev Emitted when the pause is triggered by `account`.
         */
        event Paused(address account);
    
        /**
         * @dev Emitted when the pause is lifted by `account`.
         */
        event Unpaused(address account);
    
        bool private _paused;
    
        /**
         * @dev Initializes the contract in unpaused state.
         */
        constructor() {
            _paused = false;
        }
    
        /**
         * @dev Modifier to make a function callable only when the contract is not paused.
         *
         * Requirements:
         *
         * - The contract must not be paused.
         */
        modifier whenNotPaused() {
            _requireNotPaused();
            _;
        }
    
        /**
         * @dev Modifier to make a function callable only when the contract is paused.
         *
         * Requirements:
         *
         * - The contract must be paused.
         */
        modifier whenPaused() {
            _requirePaused();
            _;
        }
    
        /**
         * @dev Returns true if the contract is paused, and false otherwise.
         */
        function paused() public view virtual returns (bool) {
            return _paused;
        }
    
        /**
         * @dev Throws if the contract is paused.
         */
        function _requireNotPaused() internal view virtual {
            require(!paused(), "Pausable: paused");
        }
    
        /**
         * @dev Throws if the contract is not paused.
         */
        function _requirePaused() internal view virtual {
            require(paused(), "Pausable: not paused");
        }
    
        /**
         * @dev Triggers stopped state.
         *
         * Requirements:
         *
         * - The contract must not be paused.
         */
        function _pause() internal virtual whenNotPaused {
            _paused = true;
            emit Paused(_msgSender());
        }
    
        /**
         * @dev Returns to normal state.
         *
         * Requirements:
         *
         * - The contract must be paused.
         */
        function _unpause() internal virtual whenPaused {
            _paused = false;
            emit Unpaused(_msgSender());
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
    
    pragma solidity ^0.8.0;
    
    import "../utils/Context.sol";
    
    /**
     * @dev Contract module which provides a basic access control mechanism, where
     * there is an account (an owner) that can be granted exclusive access to
     * specific functions.
     *
     * By default, the owner account will be the one that deploys the contract. This
     * can later be changed with {transferOwnership}.
     *
     * This module is used through inheritance. It will make available the modifier
     * `onlyOwner`, which can be applied to your functions to restrict their use to
     * the owner.
     */
    abstract contract Ownable is Context {
        address private _owner;
    
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        constructor() {
            _transferOwnership(_msgSender());
        }
    
        /**
         * @dev Throws if called by any account other than the owner.
         */
        modifier onlyOwner() {
            _checkOwner();
            _;
        }
    
        /**
         * @dev Returns the address of the current owner.
         */
        function owner() public view virtual returns (address) {
            return _owner;
        }
    
        /**
         * @dev Throws if the sender is not the owner.
         */
        function _checkOwner() internal view virtual {
            require(owner() == _msgSender(), "Ownable: caller is not the owner");
        }
    
        /**
         * @dev Leaves the contract without owner. It will not be possible to call
         * `onlyOwner` functions. Can only be called by the current owner.
         *
         * NOTE: Renouncing ownership will leave the contract without an owner,
         * thereby disabling any functionality that is only available to the owner.
         */
        function renounceOwnership() public virtual onlyOwner {
            _transferOwnership(address(0));
        }
    
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Can only be called by the current owner.
         */
        function transferOwnership(address newOwner) public virtual onlyOwner {
            require(newOwner != address(0), "Ownable: new owner is the zero address");
            _transferOwnership(newOwner);
        }
    
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Internal function without access restriction.
         */
        function _transferOwnership(address newOwner) internal virtual {
            address oldOwner = _owner;
            _owner = newOwner;
            emit OwnershipTransferred(oldOwner, newOwner);
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC721/extensions/ERC721URIStorage.sol)
    
    pragma solidity ^0.8.0;
    
    import "../ERC721.sol";
    import "../../../interfaces/IERC4906.sol";
    
    /**
     * @dev ERC721 token with storage based token URI management.
     */
    abstract contract ERC721URIStorage is IERC4906, ERC721 {
        using Strings for uint256;
    
        // Optional mapping for token URIs
        mapping(uint256 => string) private _tokenURIs;
    
        /**
         * @dev See {IERC165-supportsInterface}
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override(ERC721, IERC165) returns (bool) {
            return interfaceId == bytes4(0x49064906) || super.supportsInterface(interfaceId);
        }
    
        /**
         * @dev See {IERC721Metadata-tokenURI}.
         */
        function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
            _requireMinted(tokenId);
    
            string memory _tokenURI = _tokenURIs[tokenId];
            string memory base = _baseURI();
    
            // If there is no base URI, return the token URI.
            if (bytes(base).length == 0) {
                return _tokenURI;
            }
            // If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
            if (bytes(_tokenURI).length > 0) {
                return string(abi.encodePacked(base, _tokenURI));
            }
    
            return super.tokenURI(tokenId);
        }
    
        /**
         * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.
         *
         * Emits {MetadataUpdate}.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
            require(_exists(tokenId), "ERC721URIStorage: URI set of nonexistent token");
            _tokenURIs[tokenId] = _tokenURI;
    
            emit MetadataUpdate(tokenId);
        }
    
        /**
         * @dev See {ERC721-_burn}. This override additionally checks to see if a
         * token-specific URI was set for the token, and if so, it deletes the token URI from
         * the storage mapping.
         */
        function _burn(uint256 tokenId) internal virtual override {
            super._burn(tokenId);
    
            if (bytes(_tokenURIs[tokenId]).length != 0) {
                delete _tokenURIs[tokenId];
            }
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @title Counters
     * @author Matt Condon (@shrugs)
     * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
     * of elements in a mapping, issuing ERC721 ids, or counting request ids.
     *
     * Include with `using Counters for Counters.Counter;`
     */
    library Counters {
        struct Counter {
            // This variable should never be directly accessed by users of the library: interactions must be restricted to
            // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
            // this feature: see https://github.com/ethereum/solidity/issues/4637
            uint256 _value; // default: 0
        }
    
        function current(Counter storage counter) internal view returns (uint256) {
            return counter._value;
        }
    
        function increment(Counter storage counter) internal {
            unchecked {
                counter._value += 1;
            }
        }
    
        function decrement(Counter storage counter) internal {
            uint256 value = counter._value;
            require(value > 0, "Counter: decrement overflow");
            unchecked {
                counter._value = value - 1;
            }
        }
    
        function reset(Counter storage counter) internal {
            counter._value = 0;
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @dev Contract module that helps prevent reentrant calls to a function.
     *
     * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
     * available, which can be applied to functions to make sure there are no nested
     * (reentrant) calls to them.
     *
     * Note that because there is a single `nonReentrant` guard, functions marked as
     * `nonReentrant` may not call one another. This can be worked around by making
     * those functions `private`, and then adding `external` `nonReentrant` entry
     * points to them.
     *
     * TIP: If you would like to learn more about reentrancy and alternative ways
     * to protect against it, check out our blog post
     * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
     */
    abstract contract ReentrancyGuard {
        // Booleans are more expensive than uint256 or any type that takes up a full
        // word because each write operation emits an extra SLOAD to first read the
        // slot's contents, replace the bits taken up by the boolean, and then write
        // back. This is the compiler's defense against contract upgrades and
        // pointer aliasing, and it cannot be disabled.
    
        // The values being non-zero value makes deployment a bit more expensive,
        // but in exchange the refund on every call to nonReentrant will be lower in
        // amount. Since refunds are capped to a percentage of the total
        // transaction's gas, it is best to keep them low in cases like this one, to
        // increase the likelihood of the full refund coming into effect.
        uint256 private constant _NOT_ENTERED = 1;
        uint256 private constant _ENTERED = 2;
    
        uint256 private _status;
    
        constructor() {
            _status = _NOT_ENTERED;
        }
    
        /**
         * @dev Prevents a contract from calling itself, directly or indirectly.
         * Calling a `nonReentrant` function from another `nonReentrant`
         * function is not supported. It is possible to prevent this from happening
         * by making the `nonReentrant` function external, and making it call a
         * `private` function that does the actual work.
         */
        modifier nonReentrant() {
            _nonReentrantBefore();
            _;
            _nonReentrantAfter();
        }
    
        function _nonReentrantBefore() private {
            // On the first call to nonReentrant, _status will be _NOT_ENTERED
            require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
    
            // Any calls to nonReentrant after this point will fail
            _status = _ENTERED;
        }
    
        function _nonReentrantAfter() private {
            // By storing the original value once again, a refund is triggered (see
            // https://eips.ethereum.org/EIPS/eip-2200)
            _status = _NOT_ENTERED;
        }
    
        /**
         * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
         * `nonReentrant` function in the call stack.
         */
        function _reentrancyGuardEntered() internal view returns (bool) {
            return _status == _ENTERED;
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.4) (utils/Context.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @dev Provides information about the current execution context, including the
     * sender of the transaction and its data. While these are generally available
     * via msg.sender and msg.data, they should not be accessed in such a direct
     * manner, since when dealing with meta-transactions the account sending and
     * paying for execution may not be the actual sender (as far as an application
     * is concerned).
     *
     * This contract is only required for intermediate, library-like contracts.
     */
    abstract contract Context {
        function _msgSender() internal view virtual returns (address) {
            return msg.sender;
        }
    
        function _msgData() internal view virtual returns (bytes calldata) {
            return msg.data;
        }
    
        function _contextSuffixLength() internal view virtual returns (uint256) {
            return 0;
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC4906.sol)
    
    pragma solidity ^0.8.0;
    
    import "./IERC165.sol";
    import "./IERC721.sol";
    
    /// @title EIP-721 Metadata Update Extension
    interface IERC4906 is IERC165, IERC721 {
        /// @dev This event emits when the metadata of a token is changed.
        /// So that the third-party platforms such as NFT market could
        /// timely update the images and related attributes of the NFT.
        event MetadataUpdate(uint256 _tokenId);
    
        /// @dev This event emits when the metadata of a range of tokens is changed.
        /// So that the third-party platforms such as NFT market could
        /// timely update the images and related attributes of the NFTs.
        event BatchMetadataUpdate(uint256 _fromTokenId, uint256 _toTokenId);
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC721/ERC721.sol)
    
    pragma solidity ^0.8.0;
    
    import "./IERC721.sol";
    import "./IERC721Receiver.sol";
    import "./extensions/IERC721Metadata.sol";
    import "../../utils/Address.sol";
    import "../../utils/Context.sol";
    import "../../utils/Strings.sol";
    import "../../utils/introspection/ERC165.sol";
    
    /**
     * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
     * the Metadata extension, but not including the Enumerable extension, which is available separately as
     * {ERC721Enumerable}.
     */
    contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
        using Address for address;
        using Strings for uint256;
    
        // Token name
        string private _name;
    
        // Token symbol
        string private _symbol;
    
        // Mapping from token ID to owner address
        mapping(uint256 => address) private _owners;
    
        // Mapping owner address to token count
        mapping(address => uint256) private _balances;
    
        // Mapping from token ID to approved address
        mapping(uint256 => address) private _tokenApprovals;
    
        // Mapping from owner to operator approvals
        mapping(address => mapping(address => bool)) private _operatorApprovals;
    
        /**
         * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
         */
        constructor(string memory name_, string memory symbol_) {
            _name = name_;
            _symbol = symbol_;
        }
    
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
            return
                interfaceId == type(IERC721).interfaceId ||
                interfaceId == type(IERC721Metadata).interfaceId ||
                super.supportsInterface(interfaceId);
        }
    
        /**
         * @dev See {IERC721-balanceOf}.
         */
        function balanceOf(address owner) public view virtual override returns (uint256) {
            require(owner != address(0), "ERC721: address zero is not a valid owner");
            return _balances[owner];
        }
    
        /**
         * @dev See {IERC721-ownerOf}.
         */
        function ownerOf(uint256 tokenId) public view virtual override returns (address) {
            address owner = _ownerOf(tokenId);
            require(owner != address(0), "ERC721: invalid token ID");
            return owner;
        }
    
        /**
         * @dev See {IERC721Metadata-name}.
         */
        function name() public view virtual override returns (string memory) {
            return _name;
        }
    
        /**
         * @dev See {IERC721Metadata-symbol}.
         */
        function symbol() public view virtual override returns (string memory) {
            return _symbol;
        }
    
        /**
         * @dev See {IERC721Metadata-tokenURI}.
         */
        function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
            _requireMinted(tokenId);
    
            string memory baseURI = _baseURI();
            return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
        }
    
        /**
         * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
         * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
         * by default, can be overridden in child contracts.
         */
        function _baseURI() internal view virtual returns (string memory) {
            return "";
        }
    
        /**
         * @dev See {IERC721-approve}.
         */
        function approve(address to, uint256 tokenId) public virtual override {
            address owner = ERC721.ownerOf(tokenId);
            require(to != owner, "ERC721: approval to current owner");
    
            require(
                _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
                "ERC721: approve caller is not token owner or approved for all"
            );
    
            _approve(to, tokenId);
        }
    
        /**
         * @dev See {IERC721-getApproved}.
         */
        function getApproved(uint256 tokenId) public view virtual override returns (address) {
            _requireMinted(tokenId);
    
            return _tokenApprovals[tokenId];
        }
    
        /**
         * @dev See {IERC721-setApprovalForAll}.
         */
        function setApprovalForAll(address operator, bool approved) public virtual override {
            _setApprovalForAll(_msgSender(), operator, approved);
        }
    
        /**
         * @dev See {IERC721-isApprovedForAll}.
         */
        function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
            return _operatorApprovals[owner][operator];
        }
    
        /**
         * @dev See {IERC721-transferFrom}.
         */
        function transferFrom(address from, address to, uint256 tokenId) public virtual override {
            //solhint-disable-next-line max-line-length
            require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved");
    
            _transfer(from, to, tokenId);
        }
    
        /**
         * @dev See {IERC721-safeTransferFrom}.
         */
        function safeTransferFrom(address from, address to, uint256 tokenId) public virtual override {
            safeTransferFrom(from, to, tokenId, "");
        }
    
        /**
         * @dev See {IERC721-safeTransferFrom}.
         */
        function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public virtual override {
            require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved");
            _safeTransfer(from, to, tokenId, data);
        }
    
        /**
         * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
         * are aware of the ERC721 protocol to prevent tokens from being forever locked.
         *
         * `data` is additional data, it has no specified format and it is sent in call to `to`.
         *
         * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
         * implement alternative mechanisms to perform token transfer, such as signature-based.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must exist and be owned by `from`.
         * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
         *
         * Emits a {Transfer} event.
         */
        function _safeTransfer(address from, address to, uint256 tokenId, bytes memory data) internal virtual {
            _transfer(from, to, tokenId);
            require(_checkOnERC721Received(from, to, tokenId, data), "ERC721: transfer to non ERC721Receiver implementer");
        }
    
        /**
         * @dev Returns the owner of the `tokenId`. Does NOT revert if token doesn't exist
         */
        function _ownerOf(uint256 tokenId) internal view virtual returns (address) {
            return _owners[tokenId];
        }
    
        /**
         * @dev Returns whether `tokenId` exists.
         *
         * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
         *
         * Tokens start existing when they are minted (`_mint`),
         * and stop existing when they are burned (`_burn`).
         */
        function _exists(uint256 tokenId) internal view virtual returns (bool) {
            return _ownerOf(tokenId) != address(0);
        }
    
        /**
         * @dev Returns whether `spender` is allowed to manage `tokenId`.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
            address owner = ERC721.ownerOf(tokenId);
            return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
        }
    
        /**
         * @dev Safely mints `tokenId` and transfers it to `to`.
         *
         * Requirements:
         *
         * - `tokenId` must not exist.
         * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
         *
         * Emits a {Transfer} event.
         */
        function _safeMint(address to, uint256 tokenId) internal virtual {
            _safeMint(to, tokenId, "");
        }
    
        /**
         * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
         * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
         */
        function _safeMint(address to, uint256 tokenId, bytes memory data) internal virtual {
            _mint(to, tokenId);
            require(
                _checkOnERC721Received(address(0), to, tokenId, data),
                "ERC721: transfer to non ERC721Receiver implementer"
            );
        }
    
        /**
         * @dev Mints `tokenId` and transfers it to `to`.
         *
         * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
         *
         * Requirements:
         *
         * - `tokenId` must not exist.
         * - `to` cannot be the zero address.
         *
         * Emits a {Transfer} event.
         */
        function _mint(address to, uint256 tokenId) internal virtual {
            require(to != address(0), "ERC721: mint to the zero address");
            require(!_exists(tokenId), "ERC721: token already minted");
    
            _beforeTokenTransfer(address(0), to, tokenId, 1);
    
            // Check that tokenId was not minted by `_beforeTokenTransfer` hook
            require(!_exists(tokenId), "ERC721: token already minted");
    
            unchecked {
                // Will not overflow unless all 2**256 token ids are minted to the same owner.
                // Given that tokens are minted one by one, it is impossible in practice that
                // this ever happens. Might change if we allow batch minting.
                // The ERC fails to describe this case.
                _balances[to] += 1;
            }
    
            _owners[tokenId] = to;
    
            emit Transfer(address(0), to, tokenId);
    
            _afterTokenTransfer(address(0), to, tokenId, 1);
        }
    
        /**
         * @dev Destroys `tokenId`.
         * The approval is cleared when the token is burned.
         * This is an internal function that does not check if the sender is authorized to operate on the token.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         *
         * Emits a {Transfer} event.
         */
        function _burn(uint256 tokenId) internal virtual {
            address owner = ERC721.ownerOf(tokenId);
    
            _beforeTokenTransfer(owner, address(0), tokenId, 1);
    
            // Update ownership in case tokenId was transferred by `_beforeTokenTransfer` hook
            owner = ERC721.ownerOf(tokenId);
    
            // Clear approvals
            delete _tokenApprovals[tokenId];
    
            unchecked {
                // Cannot overflow, as that would require more tokens to be burned/transferred
                // out than the owner initially received through minting and transferring in.
                _balances[owner] -= 1;
            }
            delete _owners[tokenId];
    
            emit Transfer(owner, address(0), tokenId);
    
            _afterTokenTransfer(owner, address(0), tokenId, 1);
        }
    
        /**
         * @dev Transfers `tokenId` from `from` to `to`.
         *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
         *
         * Requirements:
         *
         * - `to` cannot be the zero address.
         * - `tokenId` token must be owned by `from`.
         *
         * Emits a {Transfer} event.
         */
        function _transfer(address from, address to, uint256 tokenId) internal virtual {
            require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
            require(to != address(0), "ERC721: transfer to the zero address");
    
            _beforeTokenTransfer(from, to, tokenId, 1);
    
            // Check that tokenId was not transferred by `_beforeTokenTransfer` hook
            require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
    
            // Clear approvals from the previous owner
            delete _tokenApprovals[tokenId];
    
            unchecked {
                // `_balances[from]` cannot overflow for the same reason as described in `_burn`:
                // `from`'s balance is the number of token held, which is at least one before the current
                // transfer.
                // `_balances[to]` could overflow in the conditions described in `_mint`. That would require
                // all 2**256 token ids to be minted, which in practice is impossible.
                _balances[from] -= 1;
                _balances[to] += 1;
            }
            _owners[tokenId] = to;
    
            emit Transfer(from, to, tokenId);
    
            _afterTokenTransfer(from, to, tokenId, 1);
        }
    
        /**
         * @dev Approve `to` to operate on `tokenId`
         *
         * Emits an {Approval} event.
         */
        function _approve(address to, uint256 tokenId) internal virtual {
            _tokenApprovals[tokenId] = to;
            emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
        }
    
        /**
         * @dev Approve `operator` to operate on all of `owner` tokens
         *
         * Emits an {ApprovalForAll} event.
         */
        function _setApprovalForAll(address owner, address operator, bool approved) internal virtual {
            require(owner != operator, "ERC721: approve to caller");
            _operatorApprovals[owner][operator] = approved;
            emit ApprovalForAll(owner, operator, approved);
        }
    
        /**
         * @dev Reverts if the `tokenId` has not been minted yet.
         */
        function _requireMinted(uint256 tokenId) internal view virtual {
            require(_exists(tokenId), "ERC721: invalid token ID");
        }
    
        /**
         * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
         * The call is not executed if the target address is not a contract.
         *
         * @param from address representing the previous owner of the given token ID
         * @param to target address that will receive the tokens
         * @param tokenId uint256 ID of the token to be transferred
         * @param data bytes optional data to send along with the call
         * @return bool whether the call correctly returned the expected magic value
         */
        function _checkOnERC721Received(
            address from,
            address to,
            uint256 tokenId,
            bytes memory data
        ) private returns (bool) {
            if (to.isContract()) {
                try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) {
                    return retval == IERC721Receiver.onERC721Received.selector;
                } catch (bytes memory reason) {
                    if (reason.length == 0) {
                        revert("ERC721: transfer to non ERC721Receiver implementer");
                    } else {
                        /// @solidity memory-safe-assembly
                        assembly {
                            revert(add(32, reason), mload(reason))
                        }
                    }
                }
            } else {
                return true;
            }
        }
    
        /**
         * @dev Hook that is called before any token transfer. This includes minting and burning. If {ERC721Consecutive} is
         * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
         *
         * Calling conditions:
         *
         * - When `from` and `to` are both non-zero, ``from``'s tokens will be transferred to `to`.
         * - When `from` is zero, the tokens will be minted for `to`.
         * - When `to` is zero, ``from``'s tokens will be burned.
         * - `from` and `to` are never both zero.
         * - `batchSize` is non-zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _beforeTokenTransfer(address from, address to, uint256 firstTokenId, uint256 batchSize) internal virtual {}
    
        /**
         * @dev Hook that is called after any token transfer. This includes minting and burning. If {ERC721Consecutive} is
         * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
         *
         * Calling conditions:
         *
         * - When `from` and `to` are both non-zero, ``from``'s tokens were transferred to `to`.
         * - When `from` is zero, the tokens were minted for `to`.
         * - When `to` is zero, ``from``'s tokens were burned.
         * - `from` and `to` are never both zero.
         * - `batchSize` is non-zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _afterTokenTransfer(address from, address to, uint256 firstTokenId, uint256 batchSize) internal virtual {}
    
        /**
         * @dev Unsafe write access to the balances, used by extensions that "mint" tokens using an {ownerOf} override.
         *
         * WARNING: Anyone calling this MUST ensure that the balances remain consistent with the ownership. The invariant
         * being that for any address `a` the value returned by `balanceOf(a)` must be equal to the number of tokens such
         * that `ownerOf(tokenId)` is `a`.
         */
        // solhint-disable-next-line func-name-mixedcase
        function __unsafe_increaseBalance(address account, uint256 amount) internal {
            _balances[account] += amount;
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (interfaces/IERC165.sol)
    
    pragma solidity ^0.8.0;
    
    import "../utils/introspection/IERC165.sol";

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (interfaces/IERC721.sol)
    
    pragma solidity ^0.8.0;
    
    import "../token/ERC721/IERC721.sol";

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
    
    pragma solidity ^0.8.1;
    
    /**
     * @dev Collection of functions related to the address type
     */
    library Address {
        /**
         * @dev Returns true if `account` is a contract.
         *
         * [IMPORTANT]
         * ====
         * It is unsafe to assume that an address for which this function returns
         * false is an externally-owned account (EOA) and not a contract.
         *
         * Among others, `isContract` will return false for the following
         * types of addresses:
         *
         *  - an externally-owned account
         *  - a contract in construction
         *  - an address where a contract will be created
         *  - an address where a contract lived, but was destroyed
         *
         * Furthermore, `isContract` will also return true if the target contract within
         * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
         * which only has an effect at the end of a transaction.
         * ====
         *
         * [IMPORTANT]
         * ====
         * You shouldn't rely on `isContract` to protect against flash loan attacks!
         *
         * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
         * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
         * constructor.
         * ====
         */
        function isContract(address account) internal view returns (bool) {
            // This method relies on extcodesize/address.code.length, which returns 0
            // for contracts in construction, since the code is only stored at the end
            // of the constructor execution.
    
            return account.code.length > 0;
        }
    
        /**
         * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
         * `recipient`, forwarding all available gas and reverting on errors.
         *
         * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
         * of certain opcodes, possibly making contracts go over the 2300 gas limit
         * imposed by `transfer`, making them unable to receive funds via
         * `transfer`. {sendValue} removes this limitation.
         *
         * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
         *
         * IMPORTANT: because control is transferred to `recipient`, care must be
         * taken to not create reentrancy vulnerabilities. Consider using
         * {ReentrancyGuard} or the
         * https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
         */
        function sendValue(address payable recipient, uint256 amount) internal {
            require(address(this).balance >= amount, "Address: insufficient balance");
    
            (bool success, ) = recipient.call{value: amount}("");
            require(success, "Address: unable to send value, recipient may have reverted");
        }
    
        /**
         * @dev Performs a Solidity function call using a low level `call`. A
         * plain `call` is an unsafe replacement for a function call: use this
         * function instead.
         *
         * If `target` reverts with a revert reason, it is bubbled up by this
         * function (like regular Solidity function calls).
         *
         * Returns the raw returned data. To convert to the expected return value,
         * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
         *
         * Requirements:
         *
         * - `target` must be a contract.
         * - calling `target` with `data` must not revert.
         *
         * _Available since v3.1._
         */
        function functionCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionCallWithValue(target, data, 0, "Address: low-level call failed");
        }
    
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
         * `errorMessage` as a fallback revert reason when `target` reverts.
         *
         * _Available since v3.1._
         */
        function functionCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal returns (bytes memory) {
            return functionCallWithValue(target, data, 0, errorMessage);
        }
    
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but also transferring `value` wei to `target`.
         *
         * Requirements:
         *
         * - the calling contract must have an ETH balance of at least `value`.
         * - the called Solidity function must be `payable`.
         *
         * _Available since v3.1._
         */
        function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
            return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
        }
    
        /**
         * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
         * with `errorMessage` as a fallback revert reason when `target` reverts.
         *
         * _Available since v3.1._
         */
        function functionCallWithValue(
            address target,
            bytes memory data,
            uint256 value,
            string memory errorMessage
        ) internal returns (bytes memory) {
            require(address(this).balance >= value, "Address: insufficient balance for call");
            (bool success, bytes memory returndata) = target.call{value: value}(data);
            return verifyCallResultFromTarget(target, success, returndata, errorMessage);
        }
    
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but performing a static call.
         *
         * _Available since v3.3._
         */
        function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
            return functionStaticCall(target, data, "Address: low-level static call failed");
        }
    
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
         * but performing a static call.
         *
         * _Available since v3.3._
         */
        function functionStaticCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal view returns (bytes memory) {
            (bool success, bytes memory returndata) = target.staticcall(data);
            return verifyCallResultFromTarget(target, success, returndata, errorMessage);
        }
    
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but performing a delegate call.
         *
         * _Available since v3.4._
         */
        function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionDelegateCall(target, data, "Address: low-level delegate call failed");
        }
    
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
         * but performing a delegate call.
         *
         * _Available since v3.4._
         */
        function functionDelegateCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal returns (bytes memory) {
            (bool success, bytes memory returndata) = target.delegatecall(data);
            return verifyCallResultFromTarget(target, success, returndata, errorMessage);
        }
    
        /**
         * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
         * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
         *
         * _Available since v4.8._
         */
        function verifyCallResultFromTarget(
            address target,
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal view returns (bytes memory) {
            if (success) {
                if (returndata.length == 0) {
                    // only check isContract if the call was successful and the return data is empty
                    // otherwise we already know that it was a contract
                    require(isContract(target), "Address: call to non-contract");
                }
                return returndata;
            } else {
                _revert(returndata, errorMessage);
            }
        }
    
        /**
         * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
         * revert reason or using the provided one.
         *
         * _Available since v4.3._
         */
        function verifyCallResult(
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal pure returns (bytes memory) {
            if (success) {
                return returndata;
            } else {
                _revert(returndata, errorMessage);
            }
        }
    
        function _revert(bytes memory returndata, string memory errorMessage) private pure {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @title ERC721 token receiver interface
     * @dev Interface for any contract that wants to support safeTransfers
     * from ERC721 asset contracts.
     */
    interface IERC721Receiver {
        /**
         * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
         * by `operator` from `from`, this function is called.
         *
         * It must return its Solidity selector to confirm the token transfer.
         * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
         *
         * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
         */
        function onERC721Received(
            address operator,
            address from,
            uint256 tokenId,
            bytes calldata data
        ) external returns (bytes4);
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
    
    pragma solidity ^0.8.0;
    
    import "../IERC721.sol";
    
    /**
     * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
     * @dev See https://eips.ethereum.org/EIPS/eip-721
     */
    interface IERC721Metadata is IERC721 {
        /**
         * @dev Returns the token collection name.
         */
        function name() external view returns (string memory);
    
        /**
         * @dev Returns the token collection symbol.
         */
        function symbol() external view returns (string memory);
    
        /**
         * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
         */
        function tokenURI(uint256 tokenId) external view returns (string memory);
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
    
    pragma solidity ^0.8.0;
    
    import "./math/Math.sol";
    import "./math/SignedMath.sol";
    
    /**
     * @dev String operations.
     */
    library Strings {
        bytes16 private constant _SYMBOLS = "0123456789abcdef";
        uint8 private constant _ADDRESS_LENGTH = 20;
    
        /**
         * @dev Converts a `uint256` to its ASCII `string` decimal representation.
         */
        function toString(uint256 value) internal pure returns (string memory) {
            unchecked {
                uint256 length = Math.log10(value) + 1;
                string memory buffer = new string(length);
                uint256 ptr;
                /// @solidity memory-safe-assembly
                assembly {
                    ptr := add(buffer, add(32, length))
                }
                while (true) {
                    ptr--;
                    /// @solidity memory-safe-assembly
                    assembly {
                        mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                    }
                    value /= 10;
                    if (value == 0) break;
                }
                return buffer;
            }
        }
    
        /**
         * @dev Converts a `int256` to its ASCII `string` decimal representation.
         */
        function toString(int256 value) internal pure returns (string memory) {
            return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
        }
    
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
         */
        function toHexString(uint256 value) internal pure returns (string memory) {
            unchecked {
                return toHexString(value, Math.log256(value) + 1);
            }
        }
    
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
         */
        function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
            bytes memory buffer = new bytes(2 * length + 2);
            buffer[0] = "0";
            buffer[1] = "x";
            for (uint256 i = 2 * length + 1; i > 1; --i) {
                buffer[i] = _SYMBOLS[value & 0xf];
                value >>= 4;
            }
            require(value == 0, "Strings: hex length insufficient");
            return string(buffer);
        }
    
        /**
         * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
         */
        function toHexString(address addr) internal pure returns (string memory) {
            return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
        }
    
        /**
         * @dev Returns true if the two strings are equal.
         */
        function equal(string memory a, string memory b) internal pure returns (bool) {
            return keccak256(bytes(a)) == keccak256(bytes(b));
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC721/IERC721.sol)
    
    pragma solidity ^0.8.0;
    
    import "../../utils/introspection/IERC165.sol";
    
    /**
     * @dev Required interface of an ERC721 compliant contract.
     */
    interface IERC721 is IERC165 {
        /**
         * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
         */
        event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
    
        /**
         * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
         */
        event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
    
        /**
         * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
         */
        event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
    
        /**
         * @dev Returns the number of tokens in ``owner``'s account.
         */
        function balanceOf(address owner) external view returns (uint256 balance);
    
        /**
         * @dev Returns the owner of the `tokenId` token.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function ownerOf(uint256 tokenId) external view returns (address owner);
    
        /**
         * @dev Safely transfers `tokenId` token from `from` to `to`.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must exist and be owned by `from`.
         * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
         * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
         *
         * Emits a {Transfer} event.
         */
        function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
    
        /**
         * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
         * are aware of the ERC721 protocol to prevent tokens from being forever locked.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must exist and be owned by `from`.
         * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
         * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
         *
         * Emits a {Transfer} event.
         */
        function safeTransferFrom(address from, address to, uint256 tokenId) external;
    
        /**
         * @dev Transfers `tokenId` token from `from` to `to`.
         *
         * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
         * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
         * understand this adds an external call which potentially creates a reentrancy vulnerability.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must be owned by `from`.
         * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(address from, address to, uint256 tokenId) external;
    
        /**
         * @dev Gives permission to `to` to transfer `tokenId` token to another account.
         * The approval is cleared when the token is transferred.
         *
         * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
         *
         * Requirements:
         *
         * - The caller must own the token or be an approved operator.
         * - `tokenId` must exist.
         *
         * Emits an {Approval} event.
         */
        function approve(address to, uint256 tokenId) external;
    
        /**
         * @dev Approve or remove `operator` as an operator for the caller.
         * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
         *
         * Requirements:
         *
         * - The `operator` cannot be the caller.
         *
         * Emits an {ApprovalForAll} event.
         */
        function setApprovalForAll(address operator, bool approved) external;
    
        /**
         * @dev Returns the account approved for `tokenId` token.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function getApproved(uint256 tokenId) external view returns (address operator);
    
        /**
         * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
         *
         * See {setApprovalForAll}
         */
        function isApprovedForAll(address owner, address operator) external view returns (bool);
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
    
    pragma solidity ^0.8.0;
    
    import "./IERC165.sol";
    
    /**
     * @dev Implementation of the {IERC165} interface.
     *
     * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
     * for the additional interface id that will be supported. For example:
     *
     * ```solidity
     * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
     *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
     * }
     * ```
     *
     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
     */
    abstract contract ERC165 is IERC165 {
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IERC165).interfaceId;
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @dev Interface of the ERC165 standard, as defined in the
     * https://eips.ethereum.org/EIPS/eip-165[EIP].
     *
     * Implementers can declare support of contract interfaces, which can then be
     * queried by others ({ERC165Checker}).
     *
     * For an implementation, see {ERC165}.
     */
    interface IERC165 {
        /**
         * @dev Returns true if this contract implements the interface defined by
         * `interfaceId`. See the corresponding
         * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
         * to learn more about how these ids are created.
         *
         * This function call must use less than 30 000 gas.
         */
        function supportsInterface(bytes4 interfaceId) external view returns (bool);
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @dev Standard math utilities missing in the Solidity language.
     */
    library Math {
        enum Rounding {
            Down, // Toward negative infinity
            Up, // Toward infinity
            Zero // Toward zero
        }
    
        /**
         * @dev Returns the largest of two numbers.
         */
        function max(uint256 a, uint256 b) internal pure returns (uint256) {
            return a > b ? a : b;
        }
    
        /**
         * @dev Returns the smallest of two numbers.
         */
        function min(uint256 a, uint256 b) internal pure returns (uint256) {
            return a < b ? a : b;
        }
    
        /**
         * @dev Returns the average of two numbers. The result is rounded towards
         * zero.
         */
        function average(uint256 a, uint256 b) internal pure returns (uint256) {
            // (a + b) / 2 can overflow.
            return (a & b) + (a ^ b) / 2;
        }
    
        /**
         * @dev Returns the ceiling of the division of two numbers.
         *
         * This differs from standard division with `/` in that it rounds up instead
         * of rounding down.
         */
        function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
            // (a + b - 1) / b can overflow on addition, so we distribute.
            return a == 0 ? 0 : (a - 1) / b + 1;
        }
    
        /**
         * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
         * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
         * with further edits by Uniswap Labs also under MIT license.
         */
        function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
            unchecked {
                // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
                // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
                // variables such that product = prod1 * 2^256 + prod0.
                uint256 prod0; // Least significant 256 bits of the product
                uint256 prod1; // Most significant 256 bits of the product
                assembly {
                    let mm := mulmod(x, y, not(0))
                    prod0 := mul(x, y)
                    prod1 := sub(sub(mm, prod0), lt(mm, prod0))
                }
    
                // Handle non-overflow cases, 256 by 256 division.
                if (prod1 == 0) {
                    // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                    // The surrounding unchecked block does not change this fact.
                    // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                    return prod0 / denominator;
                }
    
                // Make sure the result is less than 2^256. Also prevents denominator == 0.
                require(denominator > prod1, "Math: mulDiv overflow");
    
                ///////////////////////////////////////////////
                // 512 by 256 division.
                ///////////////////////////////////////////////
    
                // Make division exact by subtracting the remainder from [prod1 prod0].
                uint256 remainder;
                assembly {
                    // Compute remainder using mulmod.
                    remainder := mulmod(x, y, denominator)
    
                    // Subtract 256 bit number from 512 bit number.
                    prod1 := sub(prod1, gt(remainder, prod0))
                    prod0 := sub(prod0, remainder)
                }
    
                // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
                // See https://cs.stackexchange.com/q/138556/92363.
    
                // Does not overflow because the denominator cannot be zero at this stage in the function.
                uint256 twos = denominator & (~denominator + 1);
                assembly {
                    // Divide denominator by twos.
                    denominator := div(denominator, twos)
    
                    // Divide [prod1 prod0] by twos.
                    prod0 := div(prod0, twos)
    
                    // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                    twos := add(div(sub(0, twos), twos), 1)
                }
    
                // Shift in bits from prod1 into prod0.
                prod0 |= prod1 * twos;
    
                // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
                // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
                // four bits. That is, denominator * inv = 1 mod 2^4.
                uint256 inverse = (3 * denominator) ^ 2;
    
                // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
                // in modular arithmetic, doubling the correct bits in each step.
                inverse *= 2 - denominator * inverse; // inverse mod 2^8
                inverse *= 2 - denominator * inverse; // inverse mod 2^16
                inverse *= 2 - denominator * inverse; // inverse mod 2^32
                inverse *= 2 - denominator * inverse; // inverse mod 2^64
                inverse *= 2 - denominator * inverse; // inverse mod 2^128
                inverse *= 2 - denominator * inverse; // inverse mod 2^256
    
                // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
                // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
                // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
                // is no longer required.
                result = prod0 * inverse;
                return result;
            }
        }
    
        /**
         * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
         */
        function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
            uint256 result = mulDiv(x, y, denominator);
            if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
                result += 1;
            }
            return result;
        }
    
        /**
         * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
         *
         * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
         */
        function sqrt(uint256 a) internal pure returns (uint256) {
            if (a == 0) {
                return 0;
            }
    
            // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
            //
            // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
            // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
            //
            // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
            // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
            // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
            //
            // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
            uint256 result = 1 << (log2(a) >> 1);
    
            // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
            // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
            // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
            // into the expected uint128 result.
            unchecked {
                result = (result + a / result) >> 1;
                result = (result + a / result) >> 1;
                result = (result + a / result) >> 1;
                result = (result + a / result) >> 1;
                result = (result + a / result) >> 1;
                result = (result + a / result) >> 1;
                result = (result + a / result) >> 1;
                return min(result, a / result);
            }
        }
    
        /**
         * @notice Calculates sqrt(a), following the selected rounding direction.
         */
        function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
            unchecked {
                uint256 result = sqrt(a);
                return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
            }
        }
    
        /**
         * @dev Return the log in base 2, rounded down, of a positive value.
         * Returns 0 if given 0.
         */
        function log2(uint256 value) internal pure returns (uint256) {
            uint256 result = 0;
            unchecked {
                if (value >> 128 > 0) {
                    value >>= 128;
                    result += 128;
                }
                if (value >> 64 > 0) {
                    value >>= 64;
                    result += 64;
                }
                if (value >> 32 > 0) {
                    value >>= 32;
                    result += 32;
                }
                if (value >> 16 > 0) {
                    value >>= 16;
                    result += 16;
                }
                if (value >> 8 > 0) {
                    value >>= 8;
                    result += 8;
                }
                if (value >> 4 > 0) {
                    value >>= 4;
                    result += 4;
                }
                if (value >> 2 > 0) {
                    value >>= 2;
                    result += 2;
                }
                if (value >> 1 > 0) {
                    result += 1;
                }
            }
            return result;
        }
    
        /**
         * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
         * Returns 0 if given 0.
         */
        function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
            unchecked {
                uint256 result = log2(value);
                return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
            }
        }
    
        /**
         * @dev Return the log in base 10, rounded down, of a positive value.
         * Returns 0 if given 0.
         */
        function log10(uint256 value) internal pure returns (uint256) {
            uint256 result = 0;
            unchecked {
                if (value >= 10 ** 64) {
                    value /= 10 ** 64;
                    result += 64;
                }
                if (value >= 10 ** 32) {
                    value /= 10 ** 32;
                    result += 32;
                }
                if (value >= 10 ** 16) {
                    value /= 10 ** 16;
                    result += 16;
                }
                if (value >= 10 ** 8) {
                    value /= 10 ** 8;
                    result += 8;
                }
                if (value >= 10 ** 4) {
                    value /= 10 ** 4;
                    result += 4;
                }
                if (value >= 10 ** 2) {
                    value /= 10 ** 2;
                    result += 2;
                }
                if (value >= 10 ** 1) {
                    result += 1;
                }
            }
            return result;
        }
    
        /**
         * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
         * Returns 0 if given 0.
         */
        function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
            unchecked {
                uint256 result = log10(value);
                return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
            }
        }
    
        /**
         * @dev Return the log in base 256, rounded down, of a positive value.
         * Returns 0 if given 0.
         *
         * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
         */
        function log256(uint256 value) internal pure returns (uint256) {
            uint256 result = 0;
            unchecked {
                if (value >> 128 > 0) {
                    value >>= 128;
                    result += 16;
                }
                if (value >> 64 > 0) {
                    value >>= 64;
                    result += 8;
                }
                if (value >> 32 > 0) {
                    value >>= 32;
                    result += 4;
                }
                if (value >> 16 > 0) {
                    value >>= 16;
                    result += 2;
                }
                if (value >> 8 > 0) {
                    result += 1;
                }
            }
            return result;
        }
    
        /**
         * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
         * Returns 0 if given 0.
         */
        function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
            unchecked {
                uint256 result = log256(value);
                return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
            }
        }
    }

    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @dev Standard signed math utilities missing in the Solidity language.
     */
    library SignedMath {
        /**
         * @dev Returns the largest of two signed numbers.
         */
        function max(int256 a, int256 b) internal pure returns (int256) {
            return a > b ? a : b;
        }
    
        /**
         * @dev Returns the smallest of two signed numbers.
         */
        function min(int256 a, int256 b) internal pure returns (int256) {
            return a < b ? a : b;
        }
    
        /**
         * @dev Returns the average of two signed numbers without overflow.
         * The result is rounded towards zero.
         */
        function average(int256 a, int256 b) internal pure returns (int256) {
            // Formula from the book "Hacker's Delight"
            int256 x = (a & b) + ((a ^ b) >> 1);
            return x + (int256(uint256(x) >> 255) & (a ^ b));
        }
    
        /**
         * @dev Returns the absolute unsigned value of a signed value.
         */
        function abs(int256 n) internal pure returns (uint256) {
            unchecked {
                // must be unchecked in order to support `n = type(int256).min`
                return uint256(n >= 0 ? n : -n);
            }
        }
    }

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