// Vulnerability label: DC1
{{
  "language": "Solidity",
  "sources": {
    "MechaPenguins.sol": {
      "content": "// Sources flattened with hardhat v2.6.0 https://hardhat.org\n\n// File @openzeppelin/contracts-upgradeable/utils/introspection/IERC165Upgradeable.sol@v4.3.2\n\n// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * https://eips.ethereum.org/EIPS/eip-165[EIP].\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others ({ERC165Checker}).\n *\n * For an implementation, see {ERC165}.\n */\ninterface IERC165Upgradeable {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n\n// File @openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ninterface IERC721Upgradeable is IERC165Upgradeable {\n    /**\n     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n\n    /**\n     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.\n     */\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n\n    /**\n     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.\n     */\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of tokens in ``owner``'s account.\n     */\n    function balanceOf(address owner) external view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function ownerOf(uint256 tokenId) external view returns (address owner);\n\n    /**\n     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\n     * are aware of the ERC721 protocol to prevent tokens from being forever locked.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must exist and be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) external;\n\n    /**\n     * @dev Transfers `tokenId` token from `from` to `to`.\n     *\n     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must be owned by `from`.\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) external;\n\n    /**\n     * @dev Gives permission to `to` to transfer `tokenId` token to another account.\n     * The approval is cleared when the token is transferred.\n     *\n     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.\n     *\n     * Requirements:\n     *\n     * - The caller must own the token or be an approved operator.\n     * - `tokenId` must exist.\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address to, uint256 tokenId) external;\n\n    /**\n     * @dev Returns the account approved for `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function getApproved(uint256 tokenId) external view returns (address operator);\n\n    /**\n     * @dev Approve or remove `operator` as an operator for the caller.\n     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.\n     *\n     * Requirements:\n     *\n     * - The `operator` cannot be the caller.\n     *\n     * Emits an {ApprovalForAll} event.\n     */\n    function setApprovalForAll(address operator, bool _approved) external;\n\n    /**\n     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.\n     *\n     * See {setApprovalForAll}\n     */\n    function isApprovedForAll(address owner, address operator) external view returns (bool);\n\n    /**\n     * @dev Safely transfers `tokenId` token from `from` to `to`.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must exist and be owned by `from`.\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes calldata data\n    ) external;\n}\n\n\n// File @openzeppelin/contracts-upgradeable/token/ERC721/IERC721ReceiverUpgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ninterface IERC721ReceiverUpgradeable {\n    /**\n     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}\n     * by `operator` from `from`, this function is called.\n     *\n     * It must return its Solidity selector to confirm the token transfer.\n     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.\n     *\n     * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.\n     */\n    function onERC721Received(\n        address operator,\n        address from,\n        uint256 tokenId,\n        bytes calldata data\n    ) external returns (bytes4);\n}\n\n\n// File @openzeppelin/contracts-upgradeable/token/ERC721/extensions/IERC721MetadataUpgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ninterface IERC721MetadataUpgradeable is IERC721Upgradeable {\n    /**\n     * @dev Returns the token collection name.\n     */\n    function name() external view returns (string memory);\n\n    /**\n     * @dev Returns the token collection symbol.\n     */\n    function symbol() external view returns (string memory);\n\n    /**\n     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n\n// File @openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary AddressUpgradeable {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies on extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        assembly {\n            size := extcodesize(account)\n        }\n        return size > 0;\n    }\n\n    /**\n     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable to receive funds via\n     * `transfer`. {sendValue} removes this limitation.\n     *\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n     *\n     * IMPORTANT: because control is transferred to `recipient`, care must be\n     * taken to not create reentrancy vulnerabilities. Consider using\n     * {ReentrancyGuard} or the\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n     */\n    function sendValue(address payable recipient, uint256 amount) internal {\n        require(address(this).balance >= amount, \"Address: insufficient balance\");\n\n        (bool success, ) = recipient.call{value: amount}(\"\");\n        require(success, \"Address: unable to send value, recipient may have reverted\");\n    }\n\n    /**\n     * @dev Performs a Solidity function call using a low level `call`. A\n     * plain `call` is an unsafe replacement for a function call: use this\n     * function instead.\n     *\n     * If `target` reverts with a revert reason, it is bubbled up by this\n     * function (like regular Solidity function calls).\n     *\n     * Returns the raw returned data. To convert to the expected return value,\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n     *\n     * Requirements:\n     *\n     * - `target` must be a contract.\n     * - calling `target` with `data` must not revert.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n        return functionCall(target, data, \"Address: low-level call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n     * `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, 0, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but also transferring `value` wei to `target`.\n     *\n     * Requirements:\n     *\n     * - the calling contract must have an ETH balance of at least `value`.\n     * - the called Solidity function must be `payable`.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(\n        address target,\n        bytes memory data,\n        uint256 value\n    ) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(\n        address target,\n        bytes memory data,\n        uint256 value,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        require(address(this).balance >= value, \"Address: insufficient balance for call\");\n        require(isContract(target), \"Address: call to non-contract\");\n\n        (bool success, bytes memory returndata) = target.call{value: value}(data);\n        return verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {\n        return functionStaticCall(target, data, \"Address: low-level static call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal view returns (bytes memory) {\n        require(isContract(target), \"Address: static call to non-contract\");\n\n        (bool success, bytes memory returndata) = target.staticcall(data);\n        return verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the\n     * revert reason using the provided one.\n     *\n     * _Available since v4.3._\n     */\n    function verifyCallResult(\n        bool success,\n        bytes memory returndata,\n        string memory errorMessage\n    ) internal pure returns (bytes memory) {\n        if (success) {\n            return returndata;\n        } else {\n            // Look for revert reason and bubble it up if present\n            if (returndata.length > 0) {\n                // The easiest way to bubble the revert reason is using memory via assembly\n\n                assembly {\n                    let returndata_size := mload(returndata)\n                    revert(add(32, returndata), returndata_size)\n                }\n            } else {\n                revert(errorMessage);\n            }\n        }\n    }\n}\n\n\n// File @openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed\n * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an\n * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer\n * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.\n *\n * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as\n * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.\n *\n * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure\n * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.\n */\nabstract contract Initializable {\n    /**\n     * @dev Indicates that the contract has been initialized.\n     */\n    bool private _initialized;\n\n    /**\n     * @dev Indicates that the contract is in the process of being initialized.\n     */\n    bool private _initializing;\n\n    /**\n     * @dev Modifier to protect an initializer function from being invoked twice.\n     */\n    modifier initializer() {\n        require(_initializing || !_initialized, \"Initializable: contract is already initialized\");\n\n        bool isTopLevelCall = !_initializing;\n        if (isTopLevelCall) {\n            _initializing = true;\n            _initialized = true;\n        }\n\n        _;\n\n        if (isTopLevelCall) {\n            _initializing = false;\n        }\n    }\n}\n\n\n// File @openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract ContextUpgradeable is Initializable {\n    function __Context_init() internal initializer {\n        __Context_init_unchained();\n    }\n\n    function __Context_init_unchained() internal initializer {\n    }\n    function _msgSender() internal view virtual returns (address) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes calldata) {\n        return msg.data;\n    }\n    uint256[50] private __gap;\n}\n\n\n// File @openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @dev String operations.\n */\nlibrary StringsUpgradeable {\n    bytes16 private constant _HEX_SYMBOLS = \"0123456789abcdef\";\n\n    /**\n     * @dev Converts a `uint256` to its ASCII `string` decimal representation.\n     */\n    function toString(uint256 value) internal pure returns (string memory) {\n        // Inspired by OraclizeAPI's implementation - MIT licence\n        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol\n\n        if (value == 0) {\n            return \"0\";\n        }\n        uint256 temp = value;\n        uint256 digits;\n        while (temp != 0) {\n            digits++;\n            temp /= 10;\n        }\n        bytes memory buffer = new bytes(digits);\n        while (value != 0) {\n            digits -= 1;\n            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));\n            value /= 10;\n        }\n        return string(buffer);\n    }\n\n    /**\n     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.\n     */\n    function toHexString(uint256 value) internal pure returns (string memory) {\n        if (value == 0) {\n            return \"0x00\";\n        }\n        uint256 temp = value;\n        uint256 length = 0;\n        while (temp != 0) {\n            length++;\n            temp >>= 8;\n        }\n        return toHexString(value, length);\n    }\n\n    /**\n     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.\n     */\n    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {\n        bytes memory buffer = new bytes(2 * length + 2);\n        buffer[0] = \"0\";\n        buffer[1] = \"x\";\n        for (uint256 i = 2 * length + 1; i > 1; --i) {\n            buffer[i] = _HEX_SYMBOLS[value & 0xf];\n            value >>= 4;\n        }\n        require(value == 0, \"Strings: hex length insufficient\");\n        return string(buffer);\n    }\n}\n\n\n// File @openzeppelin/contracts-upgradeable/utils/introspection/ERC165Upgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n\n/**\n * @dev Implementation of the {IERC165} interface.\n *\n * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check\n * for the additional interface id that will be supported. For example:\n *\n * ```solidity\n * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);\n * }\n * ```\n *\n * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.\n */\nabstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {\n    function __ERC165_init() internal initializer {\n        __ERC165_init_unchained();\n    }\n\n    function __ERC165_init_unchained() internal initializer {\n    }\n    /**\n     * @dev See {IERC165-supportsInterface}.\n     */\n    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n        return interfaceId == type(IERC165Upgradeable).interfaceId;\n    }\n    uint256[50] private __gap;\n}\n\n\n// File @openzeppelin/contracts-upgradeable/token/ERC721/ERC721Upgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n\n\n\n\n\n\n\n/**\n * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including\n * the Metadata extension, but not including the Enumerable extension, which is available separately as\n * {ERC721Enumerable}.\n */\ncontract ERC721Upgradeable is Initializable, ContextUpgradeable, ERC165Upgradeable, IERC721Upgradeable, IERC721MetadataUpgradeable {\n    using AddressUpgradeable for address;\n    using StringsUpgradeable for uint256;\n\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Mapping from token ID to owner address\n    mapping(uint256 => address) private _owners;\n\n    // Mapping owner address to token count\n    mapping(address => uint256) private _balances;\n\n    // Mapping from token ID to approved address\n    mapping(uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to operator approvals\n    mapping(address => mapping(address => bool)) private _operatorApprovals;\n\n    /**\n     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.\n     */\n    function __ERC721_init(string memory name_, string memory symbol_) internal initializer {\n        __Context_init_unchained();\n        __ERC165_init_unchained();\n        __ERC721_init_unchained(name_, symbol_);\n    }\n\n    function __ERC721_init_unchained(string memory name_, string memory symbol_) internal initializer {\n        _name = name_;\n        _symbol = symbol_;\n    }\n\n    /**\n     * @dev See {IERC165-supportsInterface}.\n     */\n    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165Upgradeable, IERC165Upgradeable) returns (bool) {\n        return\n            interfaceId == type(IERC721Upgradeable).interfaceId ||\n            interfaceId == type(IERC721MetadataUpgradeable).interfaceId ||\n            super.supportsInterface(interfaceId);\n    }\n\n    /**\n     * @dev See {IERC721-balanceOf}.\n     */\n    function balanceOf(address owner) public view virtual override returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n        return _balances[owner];\n    }\n\n    /**\n     * @dev See {IERC721-ownerOf}.\n     */\n    function ownerOf(uint256 tokenId) public view virtual override returns (address) {\n        address owner = _owners[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n        return owner;\n    }\n\n    /**\n     * @dev See {IERC721Metadata-name}.\n     */\n    function name() public view virtual override returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev See {IERC721Metadata-symbol}.\n     */\n    function symbol() public view virtual override returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev See {IERC721Metadata-tokenURI}.\n     */\n    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n\n        string memory baseURI = _baseURI();\n        return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : \"\";\n    }\n\n    /**\n     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each\n     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty\n     * by default, can be overriden in child contracts.\n     */\n    function _baseURI() internal view virtual returns (string memory) {\n        return \"\";\n    }\n\n    /**\n     * @dev See {IERC721-approve}.\n     */\n    function approve(address to, uint256 tokenId) public virtual override {\n        address owner = ERC721Upgradeable.ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(\n            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _approve(to, tokenId);\n    }\n\n    /**\n     * @dev See {IERC721-getApproved}.\n     */\n    function getApproved(uint256 tokenId) public view virtual override returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev See {IERC721-setApprovalForAll}.\n     */\n    function setApprovalForAll(address operator, bool approved) public virtual override {\n        require(operator != _msgSender(), \"ERC721: approve to caller\");\n\n        _operatorApprovals[_msgSender()][operator] = approved;\n        emit ApprovalForAll(_msgSender(), operator, approved);\n    }\n\n    /**\n     * @dev See {IERC721-isApprovedForAll}.\n     */\n    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev See {IERC721-transferFrom}.\n     */\n    function transferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) public virtual override {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(_msgSender(), tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev See {IERC721-safeTransferFrom}.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) public virtual override {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev See {IERC721-safeTransferFrom}.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes memory _data\n    ) public virtual override {\n        require(_isApprovedOrOwner(_msgSender(), tokenId), \"ERC721: transfer caller is not owner nor approved\");\n        _safeTransfer(from, to, tokenId, _data);\n    }\n\n    /**\n     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\n     * are aware of the ERC721 protocol to prevent tokens from being forever locked.\n     *\n     * `_data` is additional data, it has no specified format and it is sent in call to `to`.\n     *\n     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.\n     * implement alternative mechanisms to perform token transfer, such as signature-based.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must exist and be owned by `from`.\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _safeTransfer(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes memory _data\n    ) internal virtual {\n        _transfer(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether `tokenId` exists.\n     *\n     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.\n     *\n     * Tokens start existing when they are minted (`_mint`),\n     * and stop existing when they are burned (`_burn`).\n     */\n    function _exists(uint256 tokenId) internal view virtual returns (bool) {\n        return _owners[tokenId] != address(0);\n    }\n\n    /**\n     * @dev Returns whether `spender` is allowed to manage `tokenId`.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ERC721Upgradeable.ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Safely mints `tokenId` and transfers it to `to`.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must not exist.\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _safeMint(address to, uint256 tokenId) internal virtual {\n        _safeMint(to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is\n     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.\n     */\n    function _safeMint(\n        address to,\n        uint256 tokenId,\n        bytes memory _data\n    ) internal virtual {\n        _mint(to, tokenId);\n        require(\n            _checkOnERC721Received(address(0), to, tokenId, _data),\n            \"ERC721: transfer to non ERC721Receiver implementer\"\n        );\n    }\n\n    /**\n     * @dev Mints `tokenId` and transfers it to `to`.\n     *\n     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible\n     *\n     * Requirements:\n     *\n     * - `tokenId` must not exist.\n     * - `to` cannot be the zero address.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _mint(address to, uint256 tokenId) internal virtual {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _beforeTokenTransfer(address(0), to, tokenId);\n\n        _balances[to] += 1;\n        _owners[tokenId] = to;\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Destroys `tokenId`.\n     * The approval is cleared when the token is burned.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _burn(uint256 tokenId) internal virtual {\n        address owner = ERC721Upgradeable.ownerOf(tokenId);\n\n        _beforeTokenTransfer(owner, address(0), tokenId);\n\n        // Clear approvals\n        _approve(address(0), tokenId);\n\n        _balances[owner] -= 1;\n        delete _owners[tokenId];\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Transfers `tokenId` from `from` to `to`.\n     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.\n     *\n     * Requirements:\n     *\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must be owned by `from`.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _transfer(\n        address from,\n        address to,\n        uint256 tokenId\n    ) internal virtual {\n        require(ERC721Upgradeable.ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _beforeTokenTransfer(from, to, tokenId);\n\n        // Clear approvals from the previous owner\n        _approve(address(0), tokenId);\n\n        _balances[from] -= 1;\n        _balances[to] += 1;\n        _owners[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Approve `to` to operate on `tokenId`\n     *\n     * Emits a {Approval} event.\n     */\n    function _approve(address to, uint256 tokenId) internal virtual {\n        _tokenApprovals[tokenId] = to;\n        emit Approval(ERC721Upgradeable.ownerOf(tokenId), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes memory _data\n    ) private returns (bool) {\n        if (to.isContract()) {\n            try IERC721ReceiverUpgradeable(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {\n                return retval == IERC721ReceiverUpgradeable.onERC721Received.selector;\n            } catch (bytes memory reason) {\n                if (reason.length == 0) {\n                    revert(\"ERC721: transfer to non ERC721Receiver implementer\");\n                } else {\n                    assembly {\n                        revert(add(32, reason), mload(reason))\n                    }\n                }\n            }\n        } else {\n            return true;\n        }\n    }\n\n    /**\n     * @dev Hook that is called before any token transfer. This includes minting\n     * and burning.\n     *\n     * Calling conditions:\n     *\n     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be\n     * transferred to `to`.\n     * - When `from` is zero, `tokenId` will be minted for `to`.\n     * - When `to` is zero, ``from``'s `tokenId` will be burned.\n     * - `from` and `to` are never both zero.\n     *\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n     */\n    function _beforeTokenTransfer(\n        address from,\n        address to,\n        uint256 tokenId\n    ) internal virtual {}\n    uint256[44] private __gap;\n}\n\n\n// File @openzeppelin/contracts-upgradeable/interfaces/IERC165Upgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n\n// File @openzeppelin/contracts-upgradeable/interfaces/IERC2981Upgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface for the NFT Royalty Standard\n */\ninterface IERC2981Upgradeable is IERC165Upgradeable {\n    /**\n     * @dev Called with the sale price to determine how much royalty is owed and to whom.\n     * @param tokenId - the NFT asset queried for royalty information\n     * @param salePrice - the sale price of the NFT asset specified by `tokenId`\n     * @return receiver - address of who should be sent the royalty payment\n     * @return royaltyAmount - the royalty payment amount for `salePrice`\n     */\n    function royaltyInfo(uint256 tokenId, uint256 salePrice)\n        external\n        view\n        returns (address receiver, uint256 royaltyAmount);\n}\n\n\n// File @openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {\n    address private _owner;\n\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n    function __Ownable_init() internal initializer {\n        __Context_init_unchained();\n        __Ownable_init_unchained();\n    }\n\n    function __Ownable_init_unchained() internal initializer {\n        _setOwner(_msgSender());\n    }\n\n    /**\n     * @dev Returns the address of the current owner.\n     */\n    function owner() public view virtual returns (address) {\n        return _owner;\n    }\n\n    /**\n     * @dev Throws if called by any account other than the owner.\n     */\n    modifier onlyOwner() {\n        require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n        _;\n    }\n\n    /**\n     * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby removing any functionality that is only available to the owner.\n     */\n    function renounceOwnership() public virtual onlyOwner {\n        _setOwner(address(0));\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual onlyOwner {\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n        _setOwner(newOwner);\n    }\n\n    function _setOwner(address newOwner) private {\n        address oldOwner = _owner;\n        _owner = newOwner;\n        emit OwnershipTransferred(oldOwner, newOwner);\n    }\n    uint256[49] private __gap;\n}\n\n\n// File @openzeppelin/contracts-upgradeable/utils/CountersUpgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n */\nlibrary CountersUpgradeable {\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        unchecked {\n            counter._value += 1;\n        }\n    }\n\n    function decrement(Counter storage counter) internal {\n        uint256 value = counter._value;\n        require(value > 0, \"Counter: decrement overflow\");\n        unchecked {\n            counter._value = value - 1;\n        }\n    }\n\n    function reset(Counter storage counter) internal {\n        counter._value = 0;\n    }\n}\n\n\n// File gwei-slim-nft-contracts/contracts/base/IBaseERC721Interface.sol@v1.0.3\n\n\npragma solidity 0.8.9;\n\n/// Additional features and functions assigned to the\n/// Base721 contract for hooks and overrides\ninterface IBaseERC721Interface {\n    /*\n     Exposing common NFT internal functionality for base contract overrides\n     To save gas and make API cleaner this is only for new functionality not exposed in\n     the core ERC721 contract\n    */\n\n    /// Mint an NFT. Allowed to mint by owner, approval or by the parent contract\n    /// @param tokenId id to burn\n    function __burn(uint256 tokenId) external;\n\n    /// Mint an NFT. Allowed only by the parent contract\n    /// @param to address to mint to\n    /// @param tokenId token id to mint\n    function __mint(address to, uint256 tokenId) external;\n\n    /// Set the base URI of the contract. Allowed only by parent contract\n    /// @param base base uri\n    /// @param extension extension\n    function __setBaseURI(string memory base, string memory extension) external;\n\n    /* Exposes common internal read features for public use */\n\n    /// Token exists\n    /// @param tokenId token id to see if it exists\n    function __exists(uint256 tokenId) external view returns (bool);\n\n    /// Simple approval for operation check on token for address\n    /// @param spender address spending/changing token\n    /// @param tokenId tokenID to change / operate on\n    function __isApprovedOrOwner(address spender, uint256 tokenId)\n        external\n        view\n        returns (bool);\n\n    function __isApprovedForAll(address owner, address operator)\n        external\n        view\n        returns (bool);\n\n    function __tokenURI(uint256 tokenId) external view returns (string memory);\n\n    function __owner() external view returns (address);\n}\n\n\n// File gwei-slim-nft-contracts/contracts/base/ERC721Base.sol@v1.0.3\n\n\npragma solidity 0.8.9;\n\n\n\n\n\n\nstruct ConfigSettings {\n    uint16 royaltyBps;\n    string uriBase;\n    string uriExtension;\n    bool hasTransferHook;\n}\n\n/**\n    This smart contract adds features and allows for a ownership only by another smart contract as fallback behavior\n    while also implementing all normal ERC721 functions as expected\n*/\ncontract ERC721Base is\n    ERC721Upgradeable,\n    IBaseERC721Interface,\n    IERC2981Upgradeable,\n    OwnableUpgradeable\n{\n    using CountersUpgradeable for CountersUpgradeable.Counter;\n    // Minted counter for totalSupply()\n    CountersUpgradeable.Counter private mintedCounter;\n\n    modifier onlyInternal() {\n        require(msg.sender == address(this), \"Only internal\");\n        _;\n    }\n\n    /// on-chain record of when this contract was deployed\n    uint256 public immutable deployedBlock;\n\n    ConfigSettings public advancedConfig;\n\n    /// Constructor called once when the base contract is deployed\n    constructor() {\n        // Can be used to verify contract implementation is correct at address\n        deployedBlock = block.number;\n    }\n\n    /// Initializer that's called when a new child nft is setup\n    /// @param newOwner Owner for the new derived nft\n    /// @param _name name of NFT contract\n    /// @param _symbol symbol of NFT contract\n    /// @param settings configuration settings for uri, royalty, and hooks features\n    function initialize(\n        address newOwner,\n        string memory _name,\n        string memory _symbol,\n        ConfigSettings memory settings\n    ) public initializer {\n        __ERC721_init(_name, _symbol);\n        __Ownable_init();\n\n        advancedConfig = settings;\n\n        transferOwnership(newOwner);\n    }\n\n    /// Getter to expose appoval status to root contract\n    function isApprovedForAll(address _owner, address operator)\n        public\n        view\n        override\n        returns (bool)\n    {\n        return\n            ERC721Upgradeable.isApprovedForAll(_owner, operator) ||\n            operator == address(this);\n    }\n\n    /// internal getter for approval by all\n    /// When isApprovedForAll is overridden, this can be used to call original impl\n    function __isApprovedForAll(address _owner, address operator)\n        public\n        view\n        override\n        returns (bool)\n    {\n        return isApprovedForAll(_owner, operator);\n    }\n\n    /// Hook that when enabled manually calls _beforeTokenTransfer on\n    function _beforeTokenTransfer(\n        address from,\n        address to,\n        uint256 tokenId\n    ) internal override {\n        if (advancedConfig.hasTransferHook) {\n            (bool success, ) = address(this).delegatecall(\n                abi.encodeWithSignature(\n                    \"_beforeTokenTransfer(address,address,uint256)\",\n                    from,\n                    to,\n                    tokenId\n                )\n            );\n            // Raise error again from result if error exists\n            assembly {\n                switch success\n                // delegatecall returns 0 on error.\n                case 0 {\n                    returndatacopy(0, 0, returndatasize())\n                    revert(0, returndatasize())\n                }\n            }\n        }\n    }\n\n    /// Internal-only function to update the base uri\n    function __setBaseURI(string memory uriBase, string memory uriExtension)\n        public\n        override\n        onlyInternal\n    {\n        advancedConfig.uriBase = uriBase;\n        advancedConfig.uriExtension = uriExtension;\n    }\n\n    /// @dev returns the number of minted tokens\n    /// uses some extra gas but makes etherscan and users happy so :shrug:\n    /// partial erc721enumerable implemntation\n    function totalSupply() public view returns (uint256) {\n        return mintedCounter.current();\n    }\n\n    /**\n      Internal-only\n      @param to address to send the newly minted NFT to\n      @dev This mints one edition to the given address by an allowed minter on the edition instance.\n     */\n    function __mint(address to, uint256 tokenId)\n        external\n        override\n        onlyInternal\n    {\n        _mint(to, tokenId);\n        mintedCounter.increment();\n    }\n\n    /**\n        @param tokenId Token ID to burn\n        User burn function for token id\n     */\n    function burn(uint256 tokenId) public {\n        require(_isApprovedOrOwner(_msgSender(), tokenId), \"Not allowed\");\n        _burn(tokenId);\n        mintedCounter.decrement();\n    }\n\n    /// Internal only\n    function __burn(uint256 tokenId) public onlyInternal {\n        _burn(tokenId);\n        mintedCounter.decrement();\n    }\n\n    /**\n        Simple override for owner interface.\n     */\n    function owner()\n        public\n        view\n        override(OwnableUpgradeable)\n        returns (address)\n    {\n        return super.owner();\n    }\n\n    /// internal alias for overrides\n    function __owner()\n        public\n        view\n        override(IBaseERC721Interface)\n        returns (address)\n    {\n        return owner();\n    }\n\n    /// Get royalty information for token\n    /// ignored token id to get royalty info. able to override and set per-token royalties\n    /// @param _salePrice sales price for token to determine royalty split\n    function royaltyInfo(uint256, uint256 _salePrice)\n        external\n        view\n        override\n        returns (address receiver, uint256 royaltyAmount)\n    {\n        // If ownership is revoked, don't set royalties.\n        if (owner() == address(0x0)) {\n            return (owner(), 0);\n        }\n        return (owner(), (_salePrice * advancedConfig.royaltyBps) / 10_000);\n    }\n\n    /// Default simple token-uri implementation. works for ipfs folders too\n    /// @param tokenId token id ot get uri for\n    /// @return default uri getter functionality\n    function tokenURI(uint256 tokenId)\n        public\n        view\n        override\n        returns (string memory)\n    {\n        require(_exists(tokenId), \"No token\");\n\n        return\n            string(\n                abi.encodePacked(\n                    advancedConfig.uriBase,\n                    StringsUpgradeable.toString(tokenId),\n                    advancedConfig.uriExtension\n                )\n            );\n    }\n\n    /// internal base override\n    function __tokenURI(uint256 tokenId)\n        public\n        view\n        onlyInternal\n        returns (string memory)\n    {\n        return tokenURI(tokenId);\n    }\n\n    /// Exposing token exists check for base contract\n    function __exists(uint256 tokenId) external view override returns (bool) {\n        return _exists(tokenId);\n    }\n\n    /// Getter for approved or owner\n    function __isApprovedOrOwner(address spender, uint256 tokenId)\n        external\n        view\n        override\n        onlyInternal\n        returns (bool)\n    {\n        return _isApprovedOrOwner(spender, tokenId);\n    }\n\n    /// IERC165 getter\n    /// @param interfaceId interfaceId bytes4 to check support for\n    function supportsInterface(bytes4 interfaceId)\n        public\n        view\n        override(ERC721Upgradeable, IERC165Upgradeable)\n        returns (bool)\n    {\n        return\n            type(IERC2981Upgradeable).interfaceId == interfaceId ||\n            type(IBaseERC721Interface).interfaceId == interfaceId ||\n            ERC721Upgradeable.supportsInterface(interfaceId);\n    }\n}\n\n\n// File @openzeppelin/contracts-upgradeable/utils/StorageSlotUpgradeable.sol@v4.3.2\n\n\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Library for reading and writing primitive types to specific storage slots.\n *\n * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.\n * This library helps with reading and writing to such slots without the need for inline assembly.\n *\n * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.\n *\n * Example usage to set ERC1967 implementation slot:\n * ```\n * contract ERC1967 {\n *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;\n *\n *     function _getImplementation() internal view returns (address) {\n *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;\n *     }\n *\n *     function _setImplementation(address newImplementation) internal {\n *         require(Address.isContract(newImplementation), \"ERC1967: new implementation is not a contract\");\n *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;\n *     }\n * }\n * ```\n *\n * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._\n */\nlibrary StorageSlotUpgradeable {\n    struct AddressSlot {\n        address value;\n    }\n\n    struct BooleanSlot {\n        bool value;\n    }\n\n    struct Bytes32Slot {\n        bytes32 value;\n    }\n\n    struct Uint256Slot {\n        uint256 value;\n    }\n\n    /**\n     * @dev Returns an `AddressSlot` with member `value` located at `slot`.\n     */\n    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {\n        assembly {\n            r.slot := slot\n        }\n    }\n\n    /**\n     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.\n     */\n    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {\n        assembly {\n            r.slot := slot\n        }\n    }\n\n    /**\n     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.\n     */\n    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {\n        assembly {\n            r.slot := slot\n        }\n    }\n\n    /**\n     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.\n     */\n    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {\n        assembly {\n            r.slot := slot\n        }\n    }\n}\n\n\n// File gwei-slim-nft-contracts/contracts/base/ERC721Delegated.sol@v1.0.3\n\n\npragma solidity 0.8.9;\n\ncontract ERC721Delegated {\n    uint256[100000] gap;\n    bytes32 internal constant _IMPLEMENTATION_SLOT =\n        0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;\n\n    // Reference to base NFT implementation\n    function implementation() public view returns (address) {\n        return\n            StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value;\n    }\n\n    function _initImplementation(address _nftImplementation) private {\n        StorageSlotUpgradeable\n            .getAddressSlot(_IMPLEMENTATION_SLOT)\n            .value = _nftImplementation;\n    }\n\n    /// Constructor that sets up the\n    constructor(\n        address _nftImplementation,\n        string memory name,\n        string memory symbol,\n        ConfigSettings memory settings\n    ) {\n        /// Removed for gas saving reasons, the check below implictly accomplishes this\n        // require(\n        //     _nftImplementation.supportsInterface(\n        //         type(IBaseERC721Interface).interfaceId\n        //     )\n        // );\n        _initImplementation(_nftImplementation);\n        (bool success, ) = _nftImplementation.delegatecall(\n            abi.encodeWithSignature(\n                \"initialize(address,string,string,(uint16,string,string,bool))\",\n                msg.sender,\n                name,\n                symbol,\n                settings\n            )\n        );\n        require(success);\n    }\n\n    /// OnlyOwner implemntation that proxies to base ownable contract for info\n    modifier onlyOwner() {\n        require(msg.sender == base().__owner(), \"Not owner\");\n        _;\n    }\n\n    /// Getter to return the base implementation contract to call methods from\n    /// Don't expose base contract to parent due to need to call private internal base functions\n    function base() private view returns (IBaseERC721Interface) {\n        return IBaseERC721Interface(address(this));\n    }\n\n    // helpers to mimic Openzeppelin internal functions\n\n    /// Getter for the contract owner\n    /// @return address owner address\n    function _owner() internal view returns (address) {\n        return base().__owner();\n    }\n\n    /// Internal burn function, only accessible from within contract\n    /// @param id nft id to burn\n    function _burn(uint256 id) internal {\n        base().__burn(id);\n    }\n\n    /// Internal mint function, only accessible from within contract\n    /// @param to address to mint NFT to\n    /// @param id nft id to mint\n    function _mint(address to, uint256 id) internal {\n        base().__mint(to, id);\n    }\n\n    /// Internal exists function to determine if fn exists\n    /// @param id nft id to check if exists\n    function _exists(uint256 id) internal view returns (bool) {\n        return base().__exists(id);\n    }\n\n    /// Internal getter for tokenURI\n    /// @param tokenId id of token to get tokenURI for\n    function _tokenURI(uint256 tokenId) internal view returns (string memory) {\n        return base().__tokenURI(tokenId);\n    }\n\n    /// is approved for all getter underlying getter\n    /// @param owner to check\n    /// @param operator to check\n    function _isApprovedForAll(address owner, address operator)\n        internal\n        view\n        returns (bool)\n    {\n        return base().__isApprovedForAll(owner, operator);\n    }\n\n    /// Internal getter for approved or owner for a given operator\n    /// @param operator address of operator to check\n    /// @param id id of nft to check for\n    function _isApprovedOrOwner(address operator, uint256 id)\n        internal\n        view\n        returns (bool)\n    {\n        return base().__isApprovedOrOwner(operator, id);\n    }\n\n    /// Sets the base URI of the contract. Allowed only by parent contract\n    /// @param newUri new uri base (http://URI) followed by number string of nft followed by extension string\n    /// @param newExtension optional uri extension\n    function _setBaseURI(string memory newUri, string memory newExtension)\n        internal\n    {\n        base().__setBaseURI(newUri, newExtension);\n    }\n\n    /**\n     * @dev Delegates the current call to nftImplementation.\n     *\n     * This function does not return to its internall call site, it will return directly to the external caller.\n     */\n    function _fallback() internal virtual {\n        address impl = implementation();\n\n        assembly {\n            // Copy msg.data. We take full control of memory in this inline assembly\n            // block because it will not return to Solidity code. We overwrite the\n            // Solidity scratch pad at memory position 0.\n            calldatacopy(0, 0, calldatasize())\n\n            // Call the implementation.\n            // out and outsize are 0 because we don't know the size yet.\n            let result := delegatecall(gas(), impl, 0, calldatasize(), 0, 0)\n\n            // Copy the returned data.\n            returndatacopy(0, 0, returndatasize())\n\n            switch result\n            // delegatecall returns 0 on error.\n            case 0 {\n                revert(0, returndatasize())\n            }\n            default {\n                return(0, returndatasize())\n            }\n        }\n    }\n\n    /**\n     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other\n     * function in the contract matches the call data.\n     */\n    fallback() external virtual {\n        _fallback();\n    }\n\n    /**\n     * @dev No base NFT functions receive any value\n     */\n    receive() external payable {\n        revert();\n    }\n}\n\n\n// File contracts/MechaPenguins.sol\n\n\npragma solidity 0.8.9;\n\n\n\ncontract MechaPenguins is ERC721Delegated {\n    uint256 public constant MAX_PURCHASE_PER_TX = 20;\n\n    uint256 public MAX_SUPPLY = 13332;\n    uint256 public reserveTokenId = 8888;\n    uint256 public mintPrice = 0.12 ether;\n    bool public sale = false;\n    bool public openClaim = false;\n\n    mapping(address => bool) public allowedContracts;\n    mapping(uint256 => bool) public seen;\n\n    constructor(\n        address baseFactory\n    )\n        ERC721Delegated(\n            baseFactory,\n            \"MechaPenguins\",\n            \"MPG\",\n            ConfigSettings({\n                royaltyBps: 300,\n                uriBase: \"\",\n                uriExtension: \"\",\n                hasTransferHook: false\n            })\n        )\n    {\n    }\n\n    function claimPenguins(uint256[] memory nftTokenIds, address[] memory contractAddresses) public {\n        require(openClaim, \"Claiming not open yet\");\n        for (uint256 i = 0; i < nftTokenIds.length; i++) {\n            require(allowedContracts[contractAddresses[i]], \"Contract not allowed to mint.\");\n            ERC721Upgradeable pudgyContract = ERC721Upgradeable(contractAddresses[i]);\n            require(pudgyContract.ownerOf(nftTokenIds[i]) == msg.sender, \"You are not the owner of the penguin you are trying to claim.\");\n            if (seen[nftTokenIds[i]]) {\n                continue;\n            }\n            seen[nftTokenIds[i]] = true;\n            _mint(msg.sender, nftTokenIds[i]);\n        }\n    }\n\n    function mint(uint256 amount) public payable {\n        require(sale, \"Sale not yet open\");\n        require(reserveTokenId + amount <= MAX_SUPPLY, \"Sold Out\");\n        require(msg.value == mintPrice * amount, \"Purchase: payment incorrect\");\n        require(amount <= MAX_PURCHASE_PER_TX, \"Purchase: max purchase amount exceeded\");\n\n        for(uint256 i; i < amount; i++) {\n            _mint(msg.sender, reserveTokenId++);\n        }\n    }\n\n    function setBaseURI(string memory newUri) public onlyOwner {\n        _setBaseURI(newUri, \"\");\n    }\n\n    function addToAllowedContracts(address[] memory contractAddresses) public onlyOwner {\n        for(uint i = 0; i < contractAddresses.length; i++) {\n            allowedContracts[contractAddresses[i]] = true;\n        }\n    }\n\n    function removeFromAllowedContracts(address[] memory contractAddresses) public onlyOwner {\n        for(uint i = 0; i < contractAddresses.length; i++) {\n            allowedContracts[contractAddresses[i]] = false;\n        }\n    }\n\n    function setPrice(uint256 price) public onlyOwner {\n        mintPrice = price;\n    }\n\n    function setSupply(uint256 supply) public onlyOwner {\n        MAX_SUPPLY = supply;\n    }\n\n    function setClaim(bool shouldClaim) external onlyOwner {\n        openClaim = shouldClaim;\n    }\n\n    function setSale(bool shouldSale) external onlyOwner {\n        sale = shouldSale;\n    }\n\n    function withdraw() public onlyOwner {\n        uint balance = address(this).balance;\n        (bool success, ) = payable(msg.sender).call{value: balance}(\"\");\n        require(success, \"Transfer failed.\");\n    }\n}\n"
    }
  },
  "settings": {
    "optimizer": {
      "enabled": true,
      "runs": 200
    },
    "outputSelection": {
      "*": {
        "*": [
          "evm.bytecode",
          "evm.deployedBytecode",
          "devdoc",
          "userdoc",
          "metadata",
          "abi"
        ]
      }
    }
  }
}}