{"Address.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.2;\r\n\r\n/**\r\n * @dev Collection of functions related to the address type\r\n */\r\nlibrary Address {\r\n    /**\r\n     * @dev Returns true if `account` is a contract.\r\n     *\r\n     * [IMPORTANT]\r\n     * ====\r\n     * It is unsafe to assume that an address for which this function returns\r\n     * false is an externally-owned account (EOA) and not a contract.\r\n     *\r\n     * Among others, `isContract` will return false for the following\r\n     * types of addresses:\r\n     *\r\n     *  - an externally-owned account\r\n     *  - a contract in construction\r\n     *  - an address where a contract will be created\r\n     *  - an address where a contract lived, but was destroyed\r\n     * ====\r\n     */\r\n    function isContract(address account) internal view returns (bool) {\r\n        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts\r\n        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned\r\n        // for accounts without code, i.e. `keccak256(\u0027\u0027)`\r\n        bytes32 codehash;\r\n        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;\r\n        // solhint-disable-next-line no-inline-assembly\r\n        assembly { codehash := extcodehash(account) }\r\n        return (codehash != accountHash \u0026\u0026 codehash != 0x0);\r\n    }\r\n\r\n    /**\r\n     * @dev Replacement for Solidity\u0027s `transfer`: sends `amount` wei to\r\n     * `recipient`, forwarding all available gas and reverting on errors.\r\n     *\r\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\r\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\r\n     * imposed by `transfer`, making them unable to receive funds via\r\n     * `transfer`. {sendValue} removes this limitation.\r\n     *\r\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\r\n     *\r\n     * IMPORTANT: because control is transferred to `recipient`, care must be\r\n     * taken to not create reentrancy vulnerabilities. Consider using\r\n     * {ReentrancyGuard} or the\r\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\r\n     */\r\n    function sendValue(address payable recipient, uint256 amount) internal {\r\n        require(address(this).balance \u003e= amount, \"Address: insufficient balance\");\r\n\r\n        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value\r\n        (bool success, ) = recipient.call{ value: amount }(\"\");\r\n        require(success, \"Address: unable to send value, recipient may have reverted\");\r\n    }\r\n\r\n    /**\r\n     * @dev Performs a Solidity function call using a low level `call`. A\r\n     * plain`call` is an unsafe replacement for a function call: use this\r\n     * function instead.\r\n     *\r\n     * If `target` reverts with a revert reason, it is bubbled up by this\r\n     * function (like regular Solidity function calls).\r\n     *\r\n     * Returns the raw returned data. To convert to the expected return value,\r\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `target` must be a contract.\r\n     * - calling `target` with `data` must not revert.\r\n     *\r\n     * _Available since v3.1._\r\n     */\r\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\r\n      return functionCall(target, data, \"Address: low-level call failed\");\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\r\n     * `errorMessage` as a fallback revert reason when `target` reverts.\r\n     *\r\n     * _Available since v3.1._\r\n     */\r\n    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\r\n        return _functionCallWithValue(target, data, 0, errorMessage);\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\r\n     * but also transferring `value` wei to `target`.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - the calling contract must have an ETH balance of at least `value`.\r\n     * - the called Solidity function must be `payable`.\r\n     *\r\n     * _Available since v3.1._\r\n     */\r\n    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {\r\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\r\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\r\n     *\r\n     * _Available since v3.1._\r\n     */\r\n    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {\r\n        require(address(this).balance \u003e= value, \"Address: insufficient balance for call\");\r\n        return _functionCallWithValue(target, data, value, errorMessage);\r\n    }\r\n\r\n    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {\r\n        require(isContract(target), \"Address: call to non-contract\");\r\n\r\n        // solhint-disable-next-line avoid-low-level-calls\r\n        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);\r\n        if (success) {\r\n            return returndata;\r\n        } else {\r\n            // Look for revert reason and bubble it up if present\r\n            if (returndata.length \u003e 0) {\r\n                // The easiest way to bubble the revert reason is using memory via assembly\r\n\r\n                // solhint-disable-next-line no-inline-assembly\r\n                assembly {\r\n                    let returndata_size := mload(returndata)\r\n                    revert(add(32, returndata), returndata_size)\r\n                }\r\n            } else {\r\n                revert(errorMessage);\r\n            }\r\n        }\r\n    }\r\n}\r\n"},"Context.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/*\r\n * @dev Provides information about the current execution context, including the\r\n * sender of the transaction and its data. While these are generally available\r\n * via msg.sender and msg.data, they should not be accessed in such a direct\r\n * manner, since when dealing with GSN meta-transactions the account sending and\r\n * paying for execution may not be the actual sender (as far as an application\r\n * is concerned).\r\n *\r\n * This contract is only required for intermediate, library-like contracts.\r\n */\r\nabstract contract Context {\r\n    function _msgSender() internal view virtual returns (address payable) {\r\n        return msg.sender;\r\n    }\r\n\r\n    function _msgData() internal view virtual returns (bytes memory) {\r\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\r\n        return msg.data;\r\n    }\r\n}\r\n"},"EnumerableMap.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/**\r\n * @dev Library for managing an enumerable variant of Solidity\u0027s\r\n * https://solidity.readthedocs.io/en/latest/types.html#mapping-types[`mapping`]\r\n * type.\r\n *\r\n * Maps have the following properties:\r\n *\r\n * - Entries are added, removed, and checked for existence in constant time\r\n * (O(1)).\r\n * - Entries are enumerated in O(n). No guarantees are made on the ordering.\r\n *\r\n * ```\r\n * contract Example {\r\n *     // Add the library methods\r\n *     using EnumerableMap for EnumerableMap.UintToAddressMap;\r\n *\r\n *     // Declare a set state variable\r\n *     EnumerableMap.UintToAddressMap private myMap;\r\n * }\r\n * ```\r\n *\r\n * As of v3.0.0, only maps of type `uint256 -\u003e address` (`UintToAddressMap`) are\r\n * supported.\r\n */\r\nlibrary EnumerableMap {\r\n    // To implement this library for multiple types with as little code\r\n    // repetition as possible, we write it in terms of a generic Map type with\r\n    // bytes32 keys and values.\r\n    // The Map implementation uses private functions, and user-facing\r\n    // implementations (such as Uint256ToAddressMap) are just wrappers around\r\n    // the underlying Map.\r\n    // This means that we can only create new EnumerableMaps for types that fit\r\n    // in bytes32.\r\n\r\n    struct MapEntry {\r\n        bytes32 _key;\r\n        bytes32 _value;\r\n    }\r\n\r\n    struct Map {\r\n        // Storage of map keys and values\r\n        MapEntry[] _entries;\r\n\r\n        // Position of the entry defined by a key in the `entries` array, plus 1\r\n        // because index 0 means a key is not in the map.\r\n        mapping (bytes32 =\u003e uint256) _indexes;\r\n    }\r\n\r\n    /**\r\n     * @dev Adds a key-value pair to a map, or updates the value for an existing\r\n     * key. O(1).\r\n     *\r\n     * Returns true if the key was added to the map, that is if it was not\r\n     * already present.\r\n     */\r\n    function _set(Map storage map, bytes32 key, bytes32 value) private returns (bool) {\r\n        // We read and store the key\u0027s index to prevent multiple reads from the same storage slot\r\n        uint256 keyIndex = map._indexes[key];\r\n\r\n        if (keyIndex == 0) { // Equivalent to !contains(map, key)\r\n            map._entries.push(MapEntry({ _key: key, _value: value }));\r\n            // The entry is stored at length-1, but we add 1 to all indexes\r\n            // and use 0 as a sentinel value\r\n            map._indexes[key] = map._entries.length;\r\n            return true;\r\n        } else {\r\n            map._entries[keyIndex - 1]._value = value;\r\n            return false;\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a key-value pair from a map. O(1).\r\n     *\r\n     * Returns true if the key was removed from the map, that is if it was present.\r\n     */\r\n    function _remove(Map storage map, bytes32 key) private returns (bool) {\r\n        // We read and store the key\u0027s index to prevent multiple reads from the same storage slot\r\n        uint256 keyIndex = map._indexes[key];\r\n\r\n        if (keyIndex != 0) { // Equivalent to contains(map, key)\r\n            // To delete a key-value pair from the _entries array in O(1), we swap the entry to delete with the last one\r\n            // in the array, and then remove the last entry (sometimes called as \u0027swap and pop\u0027).\r\n            // This modifies the order of the array, as noted in {at}.\r\n\r\n            uint256 toDeleteIndex = keyIndex - 1;\r\n            uint256 lastIndex = map._entries.length - 1;\r\n\r\n            // When the entry to delete is the last one, the swap operation is unnecessary. However, since this occurs\r\n            // so rarely, we still do the swap anyway to avoid the gas cost of adding an \u0027if\u0027 statement.\r\n\r\n            MapEntry storage lastEntry = map._entries[lastIndex];\r\n\r\n            // Move the last entry to the index where the entry to delete is\r\n            map._entries[toDeleteIndex] = lastEntry;\r\n            // Update the index for the moved entry\r\n            map._indexes[lastEntry._key] = toDeleteIndex + 1; // All indexes are 1-based\r\n\r\n            // Delete the slot where the moved entry was stored\r\n            map._entries.pop();\r\n\r\n            // Delete the index for the deleted slot\r\n            delete map._indexes[key];\r\n\r\n            return true;\r\n        } else {\r\n            return false;\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the key is in the map. O(1).\r\n     */\r\n    function _contains(Map storage map, bytes32 key) private view returns (bool) {\r\n        return map._indexes[key] != 0;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of key-value pairs in the map. O(1).\r\n     */\r\n    function _length(Map storage map) private view returns (uint256) {\r\n        return map._entries.length;\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the key-value pair stored at position `index` in the map. O(1).\r\n    *\r\n    * Note that there are no guarantees on the ordering of entries inside the\r\n    * array, and it may change when more entries are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function _at(Map storage map, uint256 index) private view returns (bytes32, bytes32) {\r\n        require(map._entries.length \u003e index, \"EnumerableMap: index out of bounds\");\r\n\r\n        MapEntry storage entry = map._entries[index];\r\n        return (entry._key, entry._value);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the value associated with `key`.  O(1).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `key` must be in the map.\r\n     */\r\n    function _get(Map storage map, bytes32 key) private view returns (bytes32) {\r\n        return _get(map, key, \"EnumerableMap: nonexistent key\");\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {_get}, with a custom error message when `key` is not in the map.\r\n     */\r\n    function _get(Map storage map, bytes32 key, string memory errorMessage) private view returns (bytes32) {\r\n        uint256 keyIndex = map._indexes[key];\r\n        require(keyIndex != 0, errorMessage); // Equivalent to contains(map, key)\r\n        return map._entries[keyIndex - 1]._value; // All indexes are 1-based\r\n    }\r\n\r\n    // UintToAddressMap\r\n\r\n    struct UintToAddressMap {\r\n        Map _inner;\r\n    }\r\n\r\n    /**\r\n     * @dev Adds a key-value pair to a map, or updates the value for an existing\r\n     * key. O(1).\r\n     *\r\n     * Returns true if the key was added to the map, that is if it was not\r\n     * already present.\r\n     */\r\n    function set(UintToAddressMap storage map, uint256 key, address value) internal returns (bool) {\r\n        return _set(map._inner, bytes32(key), bytes32(uint256(value)));\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a value from a set. O(1).\r\n     *\r\n     * Returns true if the key was removed from the map, that is if it was present.\r\n     */\r\n    function remove(UintToAddressMap storage map, uint256 key) internal returns (bool) {\r\n        return _remove(map._inner, bytes32(key));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the key is in the map. O(1).\r\n     */\r\n    function contains(UintToAddressMap storage map, uint256 key) internal view returns (bool) {\r\n        return _contains(map._inner, bytes32(key));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of elements in the map. O(1).\r\n     */\r\n    function length(UintToAddressMap storage map) internal view returns (uint256) {\r\n        return _length(map._inner);\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the element stored at position `index` in the set. O(1).\r\n    * Note that there are no guarantees on the ordering of values inside the\r\n    * array, and it may change when more values are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function at(UintToAddressMap storage map, uint256 index) internal view returns (uint256, address) {\r\n        (bytes32 key, bytes32 value) = _at(map._inner, index);\r\n        return (uint256(key), address(uint256(value)));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the value associated with `key`.  O(1).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `key` must be in the map.\r\n     */\r\n    function get(UintToAddressMap storage map, uint256 key) internal view returns (address) {\r\n        return address(uint256(_get(map._inner, bytes32(key))));\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {get}, with a custom error message when `key` is not in the map.\r\n     */\r\n    function get(UintToAddressMap storage map, uint256 key, string memory errorMessage) internal view returns (address) {\r\n        return address(uint256(_get(map._inner, bytes32(key), errorMessage)));\r\n    }\r\n}\r\n"},"EnumerableSet.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/**\r\n * @dev Library for managing\r\n * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive\r\n * types.\r\n *\r\n * Sets have the following properties:\r\n *\r\n * - Elements are added, removed, and checked for existence in constant time\r\n * (O(1)).\r\n * - Elements are enumerated in O(n). No guarantees are made on the ordering.\r\n *\r\n * ```\r\n * contract Example {\r\n *     // Add the library methods\r\n *     using EnumerableSet for EnumerableSet.AddressSet;\r\n *\r\n *     // Declare a set state variable\r\n *     EnumerableSet.AddressSet private mySet;\r\n * }\r\n * ```\r\n *\r\n * As of v3.0.0, only sets of type `address` (`AddressSet`) and `uint256`\r\n * (`UintSet`) are supported.\r\n */\r\nlibrary EnumerableSet {\r\n    // To implement this library for multiple types with as little code\r\n    // repetition as possible, we write it in terms of a generic Set type with\r\n    // bytes32 values.\r\n    // The Set implementation uses private functions, and user-facing\r\n    // implementations (such as AddressSet) are just wrappers around the\r\n    // underlying Set.\r\n    // This means that we can only create new EnumerableSets for types that fit\r\n    // in bytes32.\r\n\r\n    struct Set {\r\n        // Storage of set values\r\n        bytes32[] _values;\r\n\r\n        // Position of the value in the `values` array, plus 1 because index 0\r\n        // means a value is not in the set.\r\n        mapping (bytes32 =\u003e uint256) _indexes;\r\n    }\r\n\r\n    /**\r\n     * @dev Add a value to a set. O(1).\r\n     *\r\n     * Returns true if the value was added to the set, that is if it was not\r\n     * already present.\r\n     */\r\n    function _add(Set storage set, bytes32 value) private returns (bool) {\r\n        if (!_contains(set, value)) {\r\n            set._values.push(value);\r\n            // The value is stored at length-1, but we add 1 to all indexes\r\n            // and use 0 as a sentinel value\r\n            set._indexes[value] = set._values.length;\r\n            return true;\r\n        } else {\r\n            return false;\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a value from a set. O(1).\r\n     *\r\n     * Returns true if the value was removed from the set, that is if it was\r\n     * present.\r\n     */\r\n    function _remove(Set storage set, bytes32 value) private returns (bool) {\r\n        // We read and store the value\u0027s index to prevent multiple reads from the same storage slot\r\n        uint256 valueIndex = set._indexes[value];\r\n\r\n        if (valueIndex != 0) { // Equivalent to contains(set, value)\r\n            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in\r\n            // the array, and then remove the last element (sometimes called as \u0027swap and pop\u0027).\r\n            // This modifies the order of the array, as noted in {at}.\r\n\r\n            uint256 toDeleteIndex = valueIndex - 1;\r\n            uint256 lastIndex = set._values.length - 1;\r\n\r\n            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs\r\n            // so rarely, we still do the swap anyway to avoid the gas cost of adding an \u0027if\u0027 statement.\r\n\r\n            bytes32 lastvalue = set._values[lastIndex];\r\n\r\n            // Move the last value to the index where the value to delete is\r\n            set._values[toDeleteIndex] = lastvalue;\r\n            // Update the index for the moved value\r\n            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based\r\n\r\n            // Delete the slot where the moved value was stored\r\n            set._values.pop();\r\n\r\n            // Delete the index for the deleted slot\r\n            delete set._indexes[value];\r\n\r\n            return true;\r\n        } else {\r\n            return false;\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the value is in the set. O(1).\r\n     */\r\n    function _contains(Set storage set, bytes32 value) private view returns (bool) {\r\n        return set._indexes[value] != 0;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of values on the set. O(1).\r\n     */\r\n    function _length(Set storage set) private view returns (uint256) {\r\n        return set._values.length;\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the value stored at position `index` in the set. O(1).\r\n    *\r\n    * Note that there are no guarantees on the ordering of values inside the\r\n    * array, and it may change when more values are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function _at(Set storage set, uint256 index) private view returns (bytes32) {\r\n        require(set._values.length \u003e index, \"EnumerableSet: index out of bounds\");\r\n        return set._values[index];\r\n    }\r\n\r\n    // AddressSet\r\n\r\n    struct AddressSet {\r\n        Set _inner;\r\n    }\r\n\r\n    /**\r\n     * @dev Add a value to a set. O(1).\r\n     *\r\n     * Returns true if the value was added to the set, that is if it was not\r\n     * already present.\r\n     */\r\n    function add(AddressSet storage set, address value) internal returns (bool) {\r\n        return _add(set._inner, bytes32(uint256(value)));\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a value from a set. O(1).\r\n     *\r\n     * Returns true if the value was removed from the set, that is if it was\r\n     * present.\r\n     */\r\n    function remove(AddressSet storage set, address value) internal returns (bool) {\r\n        return _remove(set._inner, bytes32(uint256(value)));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the value is in the set. O(1).\r\n     */\r\n    function contains(AddressSet storage set, address value) internal view returns (bool) {\r\n        return _contains(set._inner, bytes32(uint256(value)));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of values in the set. O(1).\r\n     */\r\n    function length(AddressSet storage set) internal view returns (uint256) {\r\n        return _length(set._inner);\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the value stored at position `index` in the set. O(1).\r\n    *\r\n    * Note that there are no guarantees on the ordering of values inside the\r\n    * array, and it may change when more values are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function at(AddressSet storage set, uint256 index) internal view returns (address) {\r\n        return address(uint256(_at(set._inner, index)));\r\n    }\r\n\r\n\r\n    // UintSet\r\n\r\n    struct UintSet {\r\n        Set _inner;\r\n    }\r\n\r\n    /**\r\n     * @dev Add a value to a set. O(1).\r\n     *\r\n     * Returns true if the value was added to the set, that is if it was not\r\n     * already present.\r\n     */\r\n    function add(UintSet storage set, uint256 value) internal returns (bool) {\r\n        return _add(set._inner, bytes32(value));\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a value from a set. O(1).\r\n     *\r\n     * Returns true if the value was removed from the set, that is if it was\r\n     * present.\r\n     */\r\n    function remove(UintSet storage set, uint256 value) internal returns (bool) {\r\n        return _remove(set._inner, bytes32(value));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the value is in the set. O(1).\r\n     */\r\n    function contains(UintSet storage set, uint256 value) internal view returns (bool) {\r\n        return _contains(set._inner, bytes32(value));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of values on the set. O(1).\r\n     */\r\n    function length(UintSet storage set) internal view returns (uint256) {\r\n        return _length(set._inner);\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the value stored at position `index` in the set. O(1).\r\n    *\r\n    * Note that there are no guarantees on the ordering of values inside the\r\n    * array, and it may change when more values are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function at(UintSet storage set, uint256 index) internal view returns (uint256) {\r\n        return uint256(_at(set._inner, index));\r\n    }\r\n}\r\n"},"ERC165.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\nimport \"./IERC165.sol\";\r\n\r\n/**\r\n * @dev Implementation of the {IERC165} interface.\r\n *\r\n * Contracts may inherit from this and call {_registerInterface} to declare\r\n * their support of an interface.\r\n */\r\ncontract ERC165 is IERC165 {\r\n    /*\r\n     * bytes4(keccak256(\u0027supportsInterface(bytes4)\u0027)) == 0x01ffc9a7\r\n     */\r\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\r\n\r\n    /**\r\n     * @dev Mapping of interface ids to whether or not it\u0027s supported.\r\n     */\r\n    mapping(bytes4 =\u003e bool) private _supportedInterfaces;\r\n\r\n    constructor () internal {\r\n        // Derived contracts need only register support for their own interfaces,\r\n        // we register support for ERC165 itself here\r\n        _registerInterface(_INTERFACE_ID_ERC165);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC165-supportsInterface}.\r\n     *\r\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\r\n     */\r\n    function supportsInterface(bytes4 interfaceId) public view override returns (bool) {\r\n        return _supportedInterfaces[interfaceId];\r\n    }\r\n\r\n    /**\r\n     * @dev Registers the contract as an implementer of the interface defined by\r\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\r\n     * registering its interface id is not required.\r\n     *\r\n     * See {IERC165-supportsInterface}.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\r\n     */\r\n    function _registerInterface(bytes4 interfaceId) internal virtual {\r\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\r\n        _supportedInterfaces[interfaceId] = true;\r\n    }\r\n}\r\n"},"ERC721BatchMintableStore.sol":{"content":"\r\n\r\npragma solidity ^0.6.0;\r\n\r\nimport \"./Context.sol\";\r\nimport \"./IERC721.sol\";\r\nimport \"./IERC721Metadata.sol\";\r\nimport \"./IERC721Enumerable.sol\";\r\nimport \"./IERC721Receiver.sol\";\r\nimport \"./ERC165.sol\";\r\nimport \"./SafeMath.sol\";\r\nimport \"./Address.sol\";\r\nimport \"./EnumerableSet.sol\";\r\nimport \"./EnumerableMap.sol\";\r\nimport \"./Strings.sol\";\r\nimport \"./Ownable.sol\";\r\n\r\n/**\r\n * @title ERC721 Non-Fungible Token Standard basic implementation\r\n * @dev see https://eips.ethereum.org/EIPS/eip-721\r\n */\r\n \r\ncontract ERC721 is\r\n    Context,\r\n    Ownable,\r\n    ERC165,\r\n    IERC721,\r\n    IERC721Metadata,\r\n    IERC721Enumerable\r\n{\r\n    using SafeMath for uint256;\r\n    using Address for address;\r\n    using EnumerableSet for EnumerableSet.UintSet;\r\n    using EnumerableMap for EnumerableMap.UintToAddressMap;\r\n    using Strings for uint256;\r\n    address public exchange;\r\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\r\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\r\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\r\n\r\n    // Mapping from holder address to their (enumerable) set of owned tokens\r\n    mapping(address =\u003e EnumerableSet.UintSet) private _holderTokens;\r\n\r\n    // Enumerable mapping from token ids to their owners\r\n    EnumerableMap.UintToAddressMap private _tokenOwners;\r\n\r\n    // Mapping from token ID to approved address\r\n    mapping(uint256 =\u003e address) private _tokenApprovals;\r\n\r\n    // Mapping from owner to operator approvals\r\n    mapping(address =\u003e mapping(address =\u003e bool)) private _operatorApprovals;\r\n\r\n    // Mapping showing the addresses batch numbers in a set\r\n    mapping(address =\u003e EnumerableSet.UintSet) private _ownersBatches;\r\n    mapping(address =\u003e uint256) public BalancesMap;\r\n    mapping(uint256 =\u003e EnumerableSet.UintSet) private _batchMax;\r\n    mapping(uint256 =\u003e owners) public _batchMintOwnersMap;\r\n\r\n    // Token name\r\n    string private _name;\r\n\r\n    // Token symbol\r\n    string private _symbol;\r\n    uint8 MIN_MINT = 2;\r\n    uint256 public MAX_MINT;\r\n    uint256 public _totalSupply = 0;\r\n    uint256 public _totalBatches;\r\n    struct owners {\r\n        uint256 start;\r\n        uint256 end;\r\n        address owner;\r\n    }\r\n\r\n    // Optional mapping for token URIs\r\n    mapping(uint256 =\u003e string) private _tokenURIs;\r\n\r\n    // Base URI\r\n    string private _baseURI;\r\n\r\n    /*\r\n     *     bytes4(keccak256(\u0027balanceOf(address)\u0027)) == 0x70a08231\r\n     *     bytes4(keccak256(\u0027ownerOf(uint256)\u0027)) == 0x6352211e\r\n     *     bytes4(keccak256(\u0027approve(address,uint256)\u0027)) == 0x095ea7b3\r\n     *     bytes4(keccak256(\u0027getApproved(uint256)\u0027)) == 0x081812fc\r\n     *     bytes4(keccak256(\u0027setApprovalForAll(address,bool)\u0027)) == 0xa22cb465\r\n     *     bytes4(keccak256(\u0027isApprovedForAll(address,address)\u0027)) == 0xe985e9c5\r\n     *     bytes4(keccak256(\u0027transferFrom(address,address,uint256)\u0027)) == 0x23b872dd\r\n     *     bytes4(keccak256(\u0027safeTransferFrom(address,address,uint256)\u0027)) == 0x42842e0e\r\n     *     bytes4(keccak256(\u0027safeTransferFrom(address,address,uint256,bytes)\u0027)) == 0xb88d4fde\r\n     *\r\n     *     =\u003e 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\r\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\r\n     */\r\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\r\n\r\n    /*\r\n     *     bytes4(keccak256(\u0027name()\u0027)) == 0x06fdde03\r\n     *     bytes4(keccak256(\u0027symbol()\u0027)) == 0x95d89b41\r\n     *     bytes4(keccak256(\u0027tokenURI(uint256)\u0027)) == 0xc87b56dd\r\n     *\r\n     *     =\u003e 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\r\n     */\r\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\r\n\r\n    /*\r\n     *     bytes4(keccak256(\u0027totalSupply()\u0027)) == 0x18160ddd\r\n     *     bytes4(keccak256(\u0027tokenOfOwnerByIndex(address,uint256)\u0027)) == 0x2f745c59\r\n     *     bytes4(keccak256(\u0027tokenByIndex(uint256)\u0027)) == 0x4f6ccce7\r\n     *\r\n     *     =\u003e 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\r\n     */\r\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\r\n\r\n    /**\r\n     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.\r\n     */\r\n    constructor(\r\n        string memory name,\r\n        string memory symbol,\r\n        string memory baseURI,\r\n        uint256 batch_amount\r\n    ) public {\r\n        _name = name;\r\n        _symbol = symbol;\r\n        _setBaseURI(baseURI);\r\n        MAX_MINT = batch_amount;\r\n        // register the supported interfaces to conform to ERC721 via ERC165\r\n        _registerInterface(_INTERFACE_ID_ERC721);\r\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\r\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-balanceOf}.\r\n     */\r\n    function balanceOf(address owner) public override view returns (uint256) {\r\n        require(\r\n            owner != address(0),\r\n            \"ERC721: balance query for the zero address\"\r\n        );\r\n      \r\n        return BalancesMap[owner];\r\n        //return _holderTokens[owner].length();\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-ownerOf}.\r\n     */\r\n    function ownerOf(uint256 tokenId) public override view returns (address) {\r\n        \r\n        if (_tokenOwners.contains(tokenId)) {\r\n            return _tokenOwners.get(tokenId);\r\n        } else {\r\n            uint256 min = tokenId.div(MAX_MINT);\r\n           \r\n            uint256 max = (tokenId.div(MIN_MINT)).add(1);\r\n            if (max \u003e _totalBatches) {\r\n                max = _totalBatches;\r\n            }\r\n\r\n            \r\n            address temp = address(0x0);\r\n            for (uint256 i = min; i \u003c max; i++) {\r\n           \r\n                if (_batchMax[i].length() \u003e= 1) {\r\n                   \r\n                    if (_batchMax[i].at(1) \u003e= tokenId) {\r\n                    \r\n                        if (\r\n                            _batchMintOwnersMap[i].start \u003c= tokenId \u0026\u0026\r\n                            _batchMintOwnersMap[i].end \u003e= tokenId\r\n                        ) {\r\n                           \r\n\r\n                            temp = _batchMintOwnersMap[i].owner;\r\n                            return temp;\r\n                        }\r\n                    }\r\n                }\r\n            }\r\n            return temp;\r\n        }\r\n        //return _tokenOwners.get(tokenId, \"ERC721: owner query for nonexistent token\");\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Metadata-name}.\r\n     */\r\n    function name() public override view returns (string memory) {\r\n        return _name;\r\n    }\r\n\r\n    function tokenOwners(address owner, uint256 index) public view returns (uint256){\r\n        (uint256 id) = _holderTokens[owner].at(index);\r\n        return (id);\r\n    }\r\n    /**\r\n     * @dev See {IERC721Metadata-symbol}.\r\n     */\r\n    function symbol() public override view returns (string memory) {\r\n        return _symbol;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Metadata-tokenURI}.\r\n     */\r\n    function tokenURI(uint256 tokenId)\r\n        public\r\n        override\r\n        view\r\n        returns (string memory)\r\n    {\r\n        require(\r\n            _exists(tokenId),\r\n            \"ERC721Metadata: URI query for nonexistent token\"\r\n        );\r\n\r\n        string memory _tokenURI = _tokenURIs[tokenId];\r\n\r\n        // If there is no base URI, return the token URI.\r\n        if (bytes(_baseURI).length == 0) {\r\n            return _tokenURI;\r\n        }\r\n        // If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).\r\n        if (bytes(_tokenURI).length \u003e 0) {\r\n            return _tokenURI;\r\n        }\r\n        // If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.\r\n        return string(abi.encodePacked(_baseURI, tokenId.toString()));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the base URI set via {_setBaseURI}. This will be\r\n     * automatically added as a prefix in {tokenURI} to each token\u0027s URI, or\r\n     * to the token ID if no specific URI is set for that token ID.\r\n     */\r\n    function baseURI() public view returns (string memory) {\r\n        return _baseURI;\r\n    }\r\n\r\n\r\n\r\n\r\n    /**\r\n     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.\r\n     */\r\n    function tokenOfOwnerByIndex(address owner, uint256 index)\r\n        public\r\n        override\r\n        view\r\n        returns (uint256)\r\n    {\r\n        if(index \u003c= _holderTokens[owner].length()){\r\n             return _holderTokens[owner].at(index);\r\n        }\r\n        \r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Enumerable-totalSupply}.\r\n     */\r\n    function totalSupply() public override view returns (uint256) {\r\n        // _tokenOwners are indexed by tokenIds, so .length() returns the number of tokenIds\r\n        return _totalSupply;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Enumerable-tokenByIndex}.\r\n     * @return tokenId at index\r\n     */\r\n    function tokenByIndex(uint256 index)\r\n        public\r\n        override\r\n        view\r\n        returns (uint256)\r\n    {\r\n       if(_exists(index)) {\r\n                return index;\r\n        } else {\r\n            revert(\"No token found at index\");\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-approve}.\r\n     */\r\n    function approve(address to, uint256 tokenId) public virtual override {\r\n        address owner = ownerOf(tokenId);\r\n        require(to != owner, \"ERC721: approval to current owner\");\r\n\r\n        require(\r\n            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),\r\n            \"ERC721: approve caller is not owner nor approved for all\"\r\n        );\r\n\r\n        _approve(to, tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-getApproved}.\r\n     */\r\n    function getApproved(uint256 tokenId)\r\n        public\r\n        override\r\n        view\r\n        returns (address)\r\n    {\r\n        require(\r\n            _exists(tokenId),\r\n            \"ERC721: approved query for nonexistent token\"\r\n        );\r\n\r\n        return _tokenApprovals[tokenId];\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-setApprovalForAll}.\r\n     */\r\n    function setApprovalForAll(address operator, bool approved)\r\n        public\r\n        virtual\r\n        override\r\n    {\r\n        require(operator != _msgSender(), \"ERC721: approve to caller\");\r\n\r\n        _operatorApprovals[_msgSender()][operator] = approved;\r\n        emit ApprovalForAll(_msgSender(), operator, approved);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-setApprovalForAll}.\r\n     */\r\n    function setApprovalForExchange( bool approved)\r\n        internal\r\n        \r\n    {\r\n        require(exchange != msg.sender, \"ERC721: approve to caller\");\r\n\r\n        _operatorApprovals[msg.sender][exchange] = approved;\r\n        emit ApprovalForAll(msg.sender, exchange, approved);\r\n    }\r\n    /**\r\n     * @dev See {IERC721-isApprovedForAll}.\r\n     */\r\n    function isApprovedForAll(address owner, address operator)\r\n        public\r\n        override\r\n        view\r\n        returns (bool)\r\n    {\r\n        return _operatorApprovals[owner][operator];\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-transferFrom}.\r\n     */\r\n    function transferFrom(\r\n        address from,\r\n        address to,\r\n        uint256 tokenId\r\n    ) public virtual override {\r\n        //solhint-disable-next-line max-line-length\r\n        require(\r\n            _isApprovedOrOwner(_msgSender(), tokenId),\r\n            \"ERC721: transfer caller is not owner nor approved\"\r\n        );\r\n\r\n        _transfer(from, to, tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-safeTransferFrom}.\r\n     */\r\n    function safeTransferFrom(\r\n        address from,\r\n        address to,\r\n        uint256 tokenId\r\n    ) public virtual override {\r\n        safeTransferFrom(from, to, tokenId, \"\");\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-safeTransferFrom}.\r\n     */\r\n    function safeTransferFrom(\r\n        address from,\r\n        address to,\r\n        uint256 tokenId,\r\n        bytes memory _data\r\n    ) public virtual override {\r\n        require(\r\n            _isApprovedOrOwner(_msgSender(), tokenId),\r\n            \"ERC721: transfer caller is not owner nor approved\"\r\n        );\r\n        _safeTransfer(from, to, tokenId, _data);\r\n    }\r\n\r\n    /**\r\n     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\r\n     * are aware of the ERC721 protocol to prevent tokens from being forever locked.\r\n     *\r\n     * `_data` is additional data, it has no specified format and it is sent in call to `to`.\r\n     *\r\n     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.\r\n     * implement alternative mecanisms to perform token transfer, such as signature-based.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must exist and be owned by `from`.\r\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function _safeTransfer(\r\n        address from,\r\n        address to,\r\n        uint256 tokenId,\r\n        bytes memory _data\r\n    ) internal virtual {\r\n        _transfer(from, to, tokenId);\r\n        require(\r\n            _checkOnERC721Received(from, to, tokenId, _data),\r\n            \"ERC721: transfer to non ERC721Receiver implementer\"\r\n        );\r\n    }\r\n\r\n    /**\r\n     * @dev Returns whether `tokenId` exists.\r\n     *\r\n     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.\r\n     *\r\n     * Tokens start existing when they are minted (`_mint`),\r\n     * and stop existing when they are burned (`_burn`).\r\n     */\r\n    function _exists(uint256 tokenId) public view returns (bool) {\r\n        if (_tokenOwners.contains(tokenId)) {\r\n            return _tokenOwners.contains(tokenId);\r\n        } else if(tokenId \u003c= totalSupply()){\r\n          \r\n            uint256 min = tokenId.div(MAX_MINT);\r\n           \r\n            uint256 max = (tokenId.div(MIN_MINT)).add(1);\r\n           \r\n            if (max \u003e _totalBatches) {\r\n                max = _totalBatches;\r\n            }\r\n\r\n           \r\n            for (uint256 i = min; i \u003c max; i++) {\r\n                \r\n                if (_batchMax[i].length() \u003e= 1) {\r\n                    if (_batchMax[i].at(1) \u003e= tokenId) {\r\n                        \r\n                        if (\r\n                            _batchMintOwnersMap[i].start \u003c= tokenId \u0026\u0026\r\n                            _batchMintOwnersMap[i].end \u003e= tokenId\r\n                        ) {\r\n                            return true;\r\n                        }\r\n                    }\r\n                }\r\n            }\r\n\r\n            return false;\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Returns whether `spender` is allowed to manage `tokenId`.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function _isApprovedOrOwner(address spender, uint256 tokenId)\r\n        internal\r\n        view\r\n        returns (bool)\r\n    {\r\n        require(\r\n            _exists(tokenId),\r\n            \"ERC721: operator query for nonexistent token\"\r\n        );\r\n        address owner = ownerOf(tokenId);\r\n        return (spender == owner ||\r\n            getApproved(tokenId) == spender ||\r\n            isApprovedForAll(owner, spender));\r\n    }\r\n\r\n\r\n\r\n    /**\r\n     * @dev Mints `tokenId` and transfers it to `to`.\r\n     *\r\n     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must not exist.\r\n     * - `to` cannot be the zero address.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function _mint(address to) internal virtual {\r\n        require(to != address(0), \"ERC721: mint to the zero address\");\r\n        _totalSupply = _totalSupply.add(1); \r\n        _holderTokens[to].add(_totalSupply);\r\n\r\n        _tokenOwners.set(_totalSupply, to);\r\n        BalancesMap[to] = BalancesMap[to].add(1);\r\n        emit Transfer(address(0), to, _totalSupply); \r\n        setApprovalForExchange(true);\r\n    }\r\n\r\n    function mint(address to) public  returns (bool) {\r\n        _mint(to);\r\n        return true;\r\n    }\r\n\r\n    function mintWithURI(address to, string memory url) public  returns (bool) {\r\n        _mint(to);\r\n        _setTokenURI(_totalSupply, url);\r\n        return true;\r\n    }\r\n    \r\n       function _mintWithURI(address to, string memory url) internal returns (bool) {\r\n        _mint(to);\r\n        _setTokenURI(_totalSupply, url);\r\n        return true;\r\n    }\r\n    /** BATCH MINT\r\n     * \r\n     * Hey nate, ever get tired of relying on others? Ever want to create your own stuff and not copy? \r\n     * Eh, probably not.... everything you\u0027ve done so far is riding on someone else\u0027s coat tails. \r\n     * \r\n     * @dev _batchMint `tokenId` and transfers it to `to`.\r\n     *\r\n     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must not exist.\r\n     * - `to` cannot be the zero address.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     *\r\n     *\r\n     */\r\n    function _batchMint(address to, uint256 count) internal virtual {\r\n      \r\n        require(to != address(0), \"ERC721: mint to the zero address\");\r\n\r\n\r\n        for (uint16 i = 0; i \u003c count; i++) {\r\n            emit Transfer(address(0), to, _totalSupply.add(i+1));\r\n        }\r\n        _batchMintOwnersMap[_totalBatches].start = _totalSupply;\r\n        _batchMintOwnersMap[_totalBatches].end = _totalSupply.add(count);\r\n        _batchMintOwnersMap[_totalBatches].owner = msg.sender;\r\n        _batchMax[_totalBatches].add(_totalSupply);\r\n        _batchMax[_totalBatches].add(count.add(_totalSupply));\r\n        _ownersBatches[msg.sender].add(count);\r\n        _totalBatches = _totalBatches.add(1);\r\n        BalancesMap[msg.sender] = BalancesMap[msg.sender].add(count);\r\n        _totalSupply = _totalSupply.add(count); \r\n        setApprovalForExchange(true);\r\n       \r\n    }\r\n\r\n\r\n    /**\r\n     * @dev Transfers `tokenId` from `from` to `to`.\r\n     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must be owned by `from`.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function _transfer(\r\n        address from,\r\n        address to,\r\n        uint256 tokenId\r\n    ) internal virtual {\r\n        require(\r\n            ownerOf(tokenId) == from,\r\n            \"ERC721: transfer of token that is not own\"\r\n        );\r\n        require(to != address(0), \"ERC721: transfer to the zero address\");\r\n\r\n        //_beforeTokenTransfer(from, to, tokenId);\r\n\r\n        // Clear approvals from the previous owner\r\n        _approve(address(0), tokenId);\r\n         BalancesMap[from] =   BalancesMap[from].sub(1);\r\n         BalancesMap[to] = BalancesMap[to].add(1);\r\n        _holderTokens[from].remove(tokenId);\r\n        _holderTokens[to].add(tokenId);\r\n\r\n        _tokenOwners.set(tokenId, to);\r\n\r\n        emit Transfer(from, to, tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function _setTokenURI(uint256 tokenId, string memory _tokenURI)\r\n        internal\r\n        virtual\r\n    {\r\n        require(\r\n            _exists(tokenId),\r\n            \"ERC721Metadata: URI set of nonexistent token\"\r\n        );\r\n        _tokenURIs[tokenId] = _tokenURI;\r\n    }\r\n\r\n    /**\r\n     * @dev Internal function to set the base URI for all token IDs. It is\r\n     * automatically added as a prefix to the value returned in {tokenURI},\r\n     * or to the token ID if {tokenURI} is empty.\r\n     */\r\n    function _setBaseURI(string memory baseURI_) internal virtual {\r\n        _baseURI = baseURI_;\r\n    }\r\n\r\n    /**\r\n     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.\r\n     * The call is not executed if the target address is not a contract.\r\n     *\r\n     * @param from address representing the previous owner of the given token ID\r\n     * @param to target address that will receive the tokens\r\n     * @param tokenId uint256 ID of the token to be transferred\r\n     * @param _data bytes optional data to send along with the call\r\n     * @return bool whether the call correctly returned the expected magic value\r\n     */\r\n    function _checkOnERC721Received(\r\n        address from,\r\n        address to,\r\n        uint256 tokenId,\r\n        bytes memory _data\r\n    ) private returns (bool) {\r\n        if (!to.isContract()) {\r\n            return true;\r\n        }\r\n        bytes memory returndata = to.functionCall(\r\n            abi.encodeWithSelector(\r\n                IERC721Receiver(to).onERC721Received.selector,\r\n                _msgSender(),\r\n                from,\r\n                tokenId,\r\n                _data\r\n            ),\r\n            \"ERC721: transfer to non ERC721Receiver implementer\"\r\n        );\r\n        bytes4 retval = abi.decode(returndata, (bytes4));\r\n        return (retval == _ERC721_RECEIVED);\r\n    }\r\n\r\n    function _approve(address to, uint256 tokenId) private {\r\n        _tokenApprovals[tokenId] = to;\r\n        emit Approval(ownerOf(tokenId), to, tokenId);\r\n    }\r\n\r\n    function batchMint(address to, uint256 count) public returns (bool) {\r\n        require(\r\n            count \u003e= MIN_MINT \u0026\u0026 count \u003c= MAX_MINT,\r\n            \"Can only mint between 2 and 2000 tokens\"\r\n        );\r\n        \r\n        _batchMint(to, count);\r\n\r\n        return true;\r\n    }\r\n     function setExchangeContract(address _exchange) onlyOwner public returns (bool){\r\n        exchange = _exchange;\r\n        return true;\r\n    }\r\n}"},"ERC721Royalties.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\nimport \"./ERC165.sol\";\r\n\r\n/**\r\n * @dev Implementation of royalties for 721s\r\n *\r\n */\r\nabstract contract Royalties is ERC165 {\r\n    /*\r\n     * ERC165 bytes to add to interface array - set in parent contract implementing this standard\r\n     *\r\n     * bytes4(keccak256(\u0027royaltyInfo()\u0027)) == 0x46e80720\r\n     * bytes4 private constant _INTERFACE_ID_ERC721ROYALTIES = 0x46e80720;\r\n     * _registerInterface(_INTERFACE_ID_ERC721ROYALTIES);\r\n     */\r\n\r\n    uint256 private royalty_amount;\r\n    address private creator;\r\n    bytes4 private constant _INTERFACE_ID_ERC721ROYALTIES = 0x46e80720;\r\n    /**\r\n    @notice This event is emitted when royalties are transfered.\r\n\r\n    @dev The marketplace would emit this event from their contracts. Or they would call royaltiesRecieved() function.\r\n\r\n    @param creator The original creator of the NFT entitled to the royalties\r\n    @param buyer The person buying the NFT on a secondary sale\r\n    @param amount The amount being paid to the creator\r\n    */\r\n    event RecievedRoyalties(\r\n        address indexed creator,\r\n        address indexed buyer,\r\n        uint256 indexed amount\r\n    );\r\n\r\n    /**\r\n     *  @notice Constructor called from the NFT being deployed with the value for the royalty in percentage and the creator who will recieve the royalty payment\r\n     *\r\n     *  @param _amount The percentage value on each sale that will be transfered to the creator\r\n     *  @param _creator The original creator of the NFT entitled to the royalties\r\n     *\r\n     */\r\n\r\n    constructor(uint256 _amount, address _creator) internal {\r\n        royalty_amount = _amount;\r\n        creator = _creator;\r\n        _registerInterface(_INTERFACE_ID_ERC721ROYALTIES);\r\n    }\r\n\r\n    /**\r\n     *      @notice Called to return the royalty amount that was set and only return that amount\r\n     */\r\n    function royaltyAmount() public view returns (uint256) {\r\n        return royalty_amount;\r\n    }\r\n\r\n    /**\r\n     *      @notice Called to return both the creator\u0027s address and the royalty percentage - this would be the main function called by marketplaces unless they specifically need just the royaltyAmount\r\n     */\r\n    function royaltyInfo() external view returns (uint256, address) {\r\n        return (royalty_amount, creator);\r\n    }\r\n\r\n    /**\r\n     *      @notice Called to verify if contract implements royalties - OPTIONAL as supportsInterface()  can be called as well.\r\n     *      @param _creator The original creator of the NFT entitled to the royalties\r\n     *      @param _buyer The buyer of the NFT in a secondary sale\r\n     *      @param _amount The amount paid for royalties on this secondary sale. (Price of ERC721 sold * Royalty Percentage)\r\n     */\r\n    function royaltiesRecieved(\r\n        address _creator,\r\n        address _buyer,\r\n        uint256 _amount\r\n    ) external {\r\n        emit RecievedRoyalties(_creator, _buyer, _amount);\r\n    }\r\n\r\n    /**\r\n     *      @notice Called to verify if contract implements royalties - OPTIONAL as supportsInterface()  can be called as well.\r\n     */\r\n    function hasRoyalties() public pure returns (bool) {\r\n        return true;\r\n    }\r\n}\r\n"},"IERC165.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/**\r\n * @dev Interface of the ERC165 standard, as defined in the\r\n * https://eips.ethereum.org/EIPS/eip-165[EIP].\r\n *\r\n * Implementers can declare support of contract interfaces, which can then be\r\n * queried by others ({ERC165Checker}).\r\n *\r\n * For an implementation, see {ERC165}.\r\n */\r\ninterface IERC165 {\r\n    /**\r\n     * @dev Returns true if this contract implements the interface defined by\r\n     * `interfaceId`. See the corresponding\r\n     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]\r\n     * to learn more about how these ids are created.\r\n     *\r\n     * This function call must use less than 30 000 gas.\r\n     */\r\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\r\n}\r\n"},"IERC721.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.2;\r\n\r\nimport \"./IERC165.sol\";\r\n\r\n/**\r\n * @dev Required interface of an ERC721 compliant contract.\r\n */\r\ninterface IERC721 is IERC165 {\r\n    /**\r\n     * @dev Emitted when `tokenId` token is transfered from `from` to `to`.\r\n     */\r\n    event Transfer(\r\n        address indexed from,\r\n        address indexed to,\r\n        uint256 indexed tokenId\r\n    );\r\n\r\n    /**\r\n     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.\r\n     */\r\n    event Approval(\r\n        address indexed owner,\r\n        address indexed approved,\r\n        uint256 indexed tokenId\r\n    );\r\n\r\n    /**\r\n     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.\r\n     */\r\n    event ApprovalForAll(\r\n        address indexed owner,\r\n        address indexed operator,\r\n        bool approved\r\n    );\r\n\r\n    /**\r\n     * @dev Returns the number of tokens in ``owner``\u0027s account.\r\n     */\r\n    function balanceOf(address owner) external view returns (uint256 balance);\r\n\r\n    /**\r\n     * @dev Returns the owner of the `tokenId` token.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function ownerOf(uint256 tokenId) external view returns (address owner);\r\n\r\n    /**\r\n     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\r\n     * are aware of the ERC721 protocol to prevent tokens from being forever locked.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must exist and be owned by `from`.\r\n     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.\r\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function safeTransferFrom(\r\n        address from,\r\n        address to,\r\n        uint256 tokenId\r\n    ) external;\r\n\r\n    /**\r\n     * @dev Transfers `tokenId` token from `from` to `to`.\r\n     *\r\n     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must be owned by `from`.\r\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function transferFrom(\r\n        address from,\r\n        address to,\r\n        uint256 tokenId\r\n    ) external;\r\n\r\n    /**\r\n     * @dev Gives permission to `to` to transfer `tokenId` token to another account.\r\n     * The approval is cleared when the token is transferred.\r\n     *\r\n     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The caller must own the token or be an approved operator.\r\n     * - `tokenId` must exist.\r\n     *\r\n     * Emits an {Approval} event.\r\n     */\r\n    function approve(address to, uint256 tokenId) external;\r\n\r\n    /**\r\n     * @dev Returns the account approved for `tokenId` token.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function getApproved(uint256 tokenId)\r\n        external\r\n        view\r\n        returns (address operator);\r\n\r\n    /**\r\n     * @dev Approve or remove `operator` as an operator for the caller.\r\n     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The `operator` cannot be the caller.\r\n     *\r\n     * Emits an {ApprovalForAll} event.\r\n     */\r\n    function setApprovalForAll(address operator, bool _approved) external;\r\n\r\n    /**\r\n     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.\r\n     *\r\n     * See {setApprovalForAll}\r\n     */\r\n    function isApprovedForAll(address owner, address operator)\r\n        external\r\n        view\r\n        returns (bool);\r\n\r\n    /**\r\n     * @dev Safely transfers `tokenId` token from `from` to `to`.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must exist and be owned by `from`.\r\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\r\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function safeTransferFrom(\r\n        address from,\r\n        address to,\r\n        uint256 tokenId,\r\n        bytes calldata data\r\n    ) external;\r\n}\r\n"},"IERC721Enumerable.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.2;\r\n\r\nimport \"./IERC721.sol\";\r\n\r\n/**\r\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\r\n * @dev See https://eips.ethereum.org/EIPS/eip-721\r\n */\r\ninterface IERC721Enumerable is IERC721 {\r\n\r\n    /**\r\n     * @dev Returns the total amount of tokens stored by the contract.\r\n     */\r\n    function totalSupply() external view returns (uint256);\r\n\r\n    /**\r\n     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.\r\n     * Use along with {balanceOf} to enumerate all of ``owner``\u0027s tokens.\r\n     */\r\n    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);\r\n\r\n    /**\r\n     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.\r\n     * Use along with {totalSupply} to enumerate all tokens.\r\n     */\r\n    function tokenByIndex(uint256 index) external view returns (uint256);\r\n}\r\n"},"IERC721Metadata.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.2;\r\n\r\nimport \"./IERC721.sol\";\r\n\r\n/**\r\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\r\n * @dev See https://eips.ethereum.org/EIPS/eip-721\r\n */\r\ninterface IERC721Metadata is IERC721 {\r\n\r\n    /**\r\n     * @dev Returns the token collection name.\r\n     */\r\n    function name() external view returns (string memory);\r\n\r\n    /**\r\n     * @dev Returns the token collection symbol.\r\n     */\r\n    function symbol() external view returns (string memory);\r\n\r\n    /**\r\n     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.\r\n     */\r\n    function tokenURI(uint256 tokenId) external view returns (string memory);\r\n}\r\n"},"IERC721Receiver.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/**\r\n * @title ERC721 token receiver interface\r\n * @dev Interface for any contract that wants to support safeTransfers\r\n * from ERC721 asset contracts.\r\n */\r\ninterface IERC721Receiver {\r\n    /**\r\n     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}\r\n     * by `operator` from `from`, this function is called.\r\n     *\r\n     * It must return its Solidity selector to confirm the token transfer.\r\n     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.\r\n     *\r\n     * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.\r\n     */\r\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data)\r\n    external returns (bytes4);\r\n}\r\n"},"IERC721Royalties.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\nimport \"./IERC165.sol\";\r\n/**\r\n * @dev Interface of the ERC165 standard, as defined in the\r\n * https://eips.ethereum.org/EIPS/eip-165[EIP].\r\n *\r\n * Implementers can declare support of contract interfaces, which can then be\r\n * queried by others ({ERC165Checker}).\r\n *\r\n * For an implementation, see {ERC165}.\r\n */\r\ninterface IERC721Royalties is IERC165 {\r\n    \r\n     /**\r\n     * @dev Emitted when `tokenId` token is transfered from `from` to `to`.\r\n     */\r\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\r\n\r\n    /**\r\n     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.\r\n     */\r\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\r\n\r\n    /**\r\n     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.\r\n     */\r\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\r\n\r\n    /**\r\n     * @dev Returns the number of tokens in ``owner``\u0027s account.\r\n     */\r\n    function balanceOf(address owner) external view returns (uint256 balance);\r\n\r\n    /**\r\n     * @dev Returns the owner of the `tokenId` token.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function ownerOf(uint256 tokenId) external view returns (address owner);\r\n\r\n    /**\r\n     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\r\n     * are aware of the ERC721 protocol to prevent tokens from being forever locked.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must exist and be owned by `from`.\r\n     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.\r\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function safeTransferFrom(address from, address to, uint256 tokenId) external;\r\n\r\n    /**\r\n     * @dev Transfers `tokenId` token from `from` to `to`.\r\n     *\r\n     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must be owned by `from`.\r\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function transferFrom(address from, address to, uint256 tokenId) external;\r\n\r\n    /**\r\n     * @dev Gives permission to `to` to transfer `tokenId` token to another account.\r\n     * The approval is cleared when the token is transferred.\r\n     *\r\n     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The caller must own the token or be an approved operator.\r\n     * - `tokenId` must exist.\r\n     *\r\n     * Emits an {Approval} event.\r\n     */\r\n    function approve(address to, uint256 tokenId) external;\r\n\r\n    /**\r\n     * @dev Returns the account approved for `tokenId` token.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function getApproved(uint256 tokenId) external view returns (address operator);\r\n\r\n    /**\r\n     * @dev Approve or remove `operator` as an operator for the caller.\r\n     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The `operator` cannot be the caller.\r\n     *\r\n     * Emits an {ApprovalForAll} event.\r\n     */\r\n    function setApprovalForAll(address operator, bool _approved) external;\r\n\r\n    /**\r\n     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.\r\n     *\r\n     * See {setApprovalForAll}\r\n     */\r\n    function isApprovedForAll(address owner, address operator) external view returns (bool);\r\n\r\n    /**\r\n      * @dev Safely transfers `tokenId` token from `from` to `to`.\r\n      *\r\n      * Requirements:\r\n      *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n      * - `tokenId` token must exist and be owned by `from`.\r\n      * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\r\n      * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\r\n      *\r\n      * Emits a {Transfer} event.\r\n      */\r\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;\r\n\r\n    /**\r\n    @notice This event is emitted when royalties are received.\r\n\r\n    @dev The marketplace would call royaltiesRecieved() function so that the NFT contracts emits this event.\r\n\r\n    @param creator The original creator of the NFT entitled to the royalties\r\n    @param buyer The person buying the NFT on a secondary sale\r\n    @param amount The amount being paid to the creator\r\n  */\r\n    event RecievedRoyalties (address indexed creator, address indexed buyer, uint256 indexed amount);\r\n    \r\n\r\n     /**\r\n     * @dev Returns true if implemented\r\n     * \r\n     * @dev this is how the marketplace can see if the contract has royalties, other than using the supportsInterface() call.\r\n     */\r\n    function hasRoyalties() external view returns (bool);\r\n\r\n     /**\r\n     * @dev Returns uint256 of the amount of percentage the royalty is set to. For example, if 1%, would return \"1\", if 50%, would return \"50\"\r\n     * \r\n     * @dev Marketplaces would need to call this during the purchase function of their marketplace - and then implement the transfer of that amount on their end\r\n     */\r\n    function royaltyAmount() external view returns (uint256);\r\n    \r\n      /**\r\n     * @dev Returns royalty amount as uint256 and address where royalties should go. \r\n     * \r\n     * @dev Marketplaces would need to call this during the purchase function of their marketplace - and then implement the transfer of that amount on their end\r\n     */\r\n    function royaltyInfo() external view returns (uint256, address);\r\n    \r\n      /**\r\n     * @dev Called by the marketplace after the transfer of royalties has happened, so that the contract has a record \r\n     * @dev emits RecievedRoyalties event;\r\n     * \r\n     * @param _creator The original creator of the NFT entitled to the royalties\r\n     * @param _buyer The person buying the NFT on a secondary sale\r\n     * @param _amount The amount being paid to the creator\r\n     */\r\n    function royaltiesRecieved(address _creator, address _buyer, uint256 _amount) external view;\r\n}\r\n"},"Ownable.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\nimport \"./Context.sol\";\r\n/**\r\n * @dev Contract module which provides a basic access control mechanism, where\r\n * there is an account (an owner) that can be granted exclusive access to\r\n * specific functions.\r\n *\r\n * By default, the owner account will be the one that deploys the contract. This\r\n * can later be changed with {transferOwnership}.\r\n *\r\n * This module is used through inheritance. It will make available the modifier\r\n * `onlyOwner`, which can be applied to your functions to restrict their use to\r\n * the owner.\r\n */\r\ncontract Ownable is Context {\r\n    address private _owner;\r\n\r\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\r\n\r\n    /**\r\n     * @dev Initializes the contract setting the deployer as the initial owner.\r\n     */\r\n    constructor () internal {\r\n        address msgSender = _msgSender();\r\n        _owner = msgSender;\r\n        emit OwnershipTransferred(address(0), msgSender);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the address of the current owner.\r\n     */\r\n    function owner() public view returns (address) {\r\n        return _owner;\r\n    }\r\n\r\n    /**\r\n     * @dev Throws if called by any account other than the owner.\r\n     */\r\n    modifier onlyOwner() {\r\n        require(_owner == _msgSender(), \"Ownable: caller is not the owner\");\r\n        _;\r\n    }\r\n\r\n    /**\r\n     * @dev Leaves the contract without owner. It will not be possible to call\r\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\r\n     *\r\n     * NOTE: Renouncing ownership will leave the contract without an owner,\r\n     * thereby removing any functionality that is only available to the owner.\r\n     */\r\n    function renounceOwnership() public virtual onlyOwner {\r\n        emit OwnershipTransferred(_owner, address(0));\r\n        _owner = address(0);\r\n    }\r\n\r\n    /**\r\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\r\n     * Can only be called by the current owner.\r\n     */\r\n    function transferOwnership(address newOwner) public virtual onlyOwner {\r\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\r\n        emit OwnershipTransferred(_owner, newOwner);\r\n        _owner = newOwner;\r\n    }\r\n}\r\n"},"PrintablePublic.sol":{"content":"  // SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\nimport \"./ERC721Royalties.sol\";\r\nimport \"./ERC721BatchMintableStore.sol\";\r\n/**\r\n * @title ERC721 Printable Token\r\n * @dev ERC721 Token that can be be printed before being sold and not incur high gas fees \r\n */\r\n contract ERC721Printable is ERC721, Royalties {\r\n     bytes4 private constant _INTERFACE_ID_ERC721ROYALTIES = 0x46e80720;\r\n\r\n\r\n  uint256 public totalSeries;\r\n  address payable public MintableAddress;\r\n  mapping(uint256 =\u003e PreMint) public PreMintData;\r\n  mapping(uint256 =\u003e bool) public PrintSeries;\r\n  struct PreMint {\r\n      uint256 amount_of_tokens_left;\r\n      uint256 price;\r\n      address payable creator;\r\n      string url;\r\n      \r\n    }  \r\n  event SeriesMade(address indexed creator, uint256 indexed price, uint256 indexed amount_made);\r\n  event SeriesPurchased(address indexed buyer, uint256 indexed token_id, uint256 indexed price); \r\n  event TransferPayment(address indexed to, uint256 indexed amount); \r\n  event TransferFee(address indexed to, uint256 indexed fee); \r\n  \r\n  \r\n   constructor(\r\n        string memory name,\r\n        string memory symbol,\r\n        string memory baseURI,\r\n        uint256 batch_amount,\r\n        uint256 royalty_amount,\r\n        address creator\r\n    ) public  ERC721(name, symbol, baseURI, batch_amount) Royalties(royalty_amount, creator) {\r\n        MintableAddress = msg.sender;\r\n        _registerInterface(_INTERFACE_ID_ERC721ROYALTIES);\r\n    }\r\n    \r\n   function _createPrintSeries(uint256 _totalAmount, uint256 _price, string memory _url) internal returns (bool){\r\n        totalSeries = totalSeries.add(1);\r\n          PrintSeries[totalSeries] = true;\r\n          \r\n          PreMintData[totalSeries].amount_of_tokens_left = _totalAmount;\r\n              PreMintData[totalSeries].price = _price;\r\n                 PreMintData[totalSeries].url = _url;\r\n                PreMintData[totalSeries].creator = msg.sender;\r\n                \r\n                emit SeriesMade(msg.sender, _price, _totalAmount);\r\n                return true;\r\n }\r\n \r\n    function createPrintSeries(uint256 _amount, uint256 _price, string memory _url) public returns (bool){\r\n        return _createPrintSeries(_amount, _price, _url);\r\n        \r\n    }\r\n    function mintSeries(uint256 _seriesID, address _to) public payable returns (bool){\r\n     require(PrintSeries[_seriesID], \"Not a valid series\");\r\n     require(PreMintData[_seriesID].amount_of_tokens_left \u003e= 1, \"Series is SOLD OUT!\");\r\n     require(msg.value \u003e= PreMintData[_seriesID].price, \"Invalid amount sent to purchase this NFT\");\r\n     //get total supply\r\n     //change the amount of tokens left to be one less\r\n     PreMintData[_seriesID].amount_of_tokens_left =  PreMintData[_seriesID].amount_of_tokens_left.sub(1);\r\n     //check if tokens left are 0 if so, set to sold out\r\n     if(PreMintData[_seriesID].amount_of_tokens_left == 0){\r\n         PrintSeries[_seriesID] = false;\r\n     }\r\n     emit SeriesPurchased( msg.sender, super.totalSupply().add(1), msg.value); \r\n     //mint tokens and send to buyer\r\n     super._mintWithURI(_to, PreMintData[_seriesID].url);\r\n     //calculate fees to be removed\r\n     uint256 fee = (msg.value.mul(5)).div(100);\r\n     uint256 creatorsPayment = msg.value.sub(fee);\r\n     //transfer payment to creator\u0027s address\r\n     PreMintData[_seriesID].creator.transfer(creatorsPayment);\r\n    require(address(this).balance \u003e= fee, \"Not enough balance to send fee\");\r\n    emit TransferPayment( PreMintData[_seriesID].creator,  creatorsPayment);\r\n    MintableAddress.transfer(fee);\r\n    emit TransferFee(MintableAddress, fee); \r\n    return true;\r\n }\r\n \r\n}\r\n\r\n  \r\n"},"SafeMath.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/**\r\n * @dev Wrappers over Solidity\u0027s arithmetic operations with added overflow\r\n * checks.\r\n *\r\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\r\n * in bugs, because programmers usually assume that an overflow raises an\r\n * error, which is the standard behavior in high level programming languages.\r\n * `SafeMath` restores this intuition by reverting the transaction when an\r\n * operation overflows.\r\n *\r\n * Using this library instead of the unchecked operations eliminates an entire\r\n * class of bugs, so it\u0027s recommended to use it always.\r\n */\r\nlibrary SafeMath {\r\n    /**\r\n     * @dev Returns the addition of two unsigned integers, reverting on\r\n     * overflow.\r\n     *\r\n     * Counterpart to Solidity\u0027s `+` operator.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - Addition cannot overflow.\r\n     */\r\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        uint256 c = a + b;\r\n        require(c \u003e= a, \"SafeMath: addition overflow\");\r\n\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the subtraction of two unsigned integers, reverting on\r\n     * overflow (when the result is negative).\r\n     *\r\n     * Counterpart to Solidity\u0027s `-` operator.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - Subtraction cannot overflow.\r\n     */\r\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        return sub(a, b, \"SafeMath: subtraction overflow\");\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\r\n     * overflow (when the result is negative).\r\n     *\r\n     * Counterpart to Solidity\u0027s `-` operator.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - Subtraction cannot overflow.\r\n     */\r\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\r\n        require(b \u003c= a, errorMessage);\r\n        uint256 c = a - b;\r\n\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the multiplication of two unsigned integers, reverting on\r\n     * overflow.\r\n     *\r\n     * Counterpart to Solidity\u0027s `*` operator.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - Multiplication cannot overflow.\r\n     */\r\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        // Gas optimization: this is cheaper than requiring \u0027a\u0027 not being zero, but the\r\n        // benefit is lost if \u0027b\u0027 is also tested.\r\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\r\n        if (a == 0) {\r\n            return 0;\r\n        }\r\n\r\n        uint256 c = a * b;\r\n        require(c / a == b, \"SafeMath: multiplication overflow\");\r\n\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the integer division of two unsigned integers. Reverts on\r\n     * division by zero. The result is rounded towards zero.\r\n     *\r\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\r\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\r\n     * uses an invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        return div(a, b, \"SafeMath: division by zero\");\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on\r\n     * division by zero. The result is rounded towards zero.\r\n     *\r\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\r\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\r\n     * uses an invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\r\n        require(b \u003e 0, errorMessage);\r\n        uint256 c = a / b;\r\n        // assert(a == b * c + a % b); // There is no case in which this doesn\u0027t hold\r\n\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\r\n     * Reverts when dividing by zero.\r\n     *\r\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\r\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\r\n     * invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        return mod(a, b, \"SafeMath: modulo by zero\");\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\r\n     * Reverts with custom message when dividing by zero.\r\n     *\r\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\r\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\r\n     * invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\r\n        require(b != 0, errorMessage);\r\n        return a % b;\r\n    }\r\n}\r\n"},"Strings.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/**\r\n * @dev String operations.\r\n */\r\nlibrary Strings {\r\n    /**\r\n     * @dev Converts a `uint256` to its ASCII `string` representation.\r\n     */\r\n    function toString(uint256 value) internal pure returns (string memory) {\r\n        // Inspired by OraclizeAPI\u0027s implementation - MIT licence\r\n        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol\r\n\r\n        if (value == 0) {\r\n            return \"0\";\r\n        }\r\n        uint256 temp = value;\r\n        uint256 digits;\r\n        while (temp != 0) {\r\n            digits++;\r\n            temp /= 10;\r\n        }\r\n        bytes memory buffer = new bytes(digits);\r\n        uint256 index = digits - 1;\r\n        temp = value;\r\n        while (temp != 0) {\r\n            buffer[index--] = byte(uint8(48 + temp % 10));\r\n            temp /= 10;\r\n        }\r\n        return string(buffer);\r\n    }\r\n}\r\n"}}