// SPDX-License-Identifier: MIT

pragma solidity 0.6.8;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive vaults via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(
            address(this).balance >= amount,
            "Address: insufficient balance"
        );

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{value: amount}("");
        require(
            success,
            "Address: unable to send value, recipient may have reverted"
        );
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data)
        internal
        returns (bytes memory)
    {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return
            functionCallWithValue(
                target,
                data,
                value,
                "Address: low-level call with value failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(
            address(this).balance >= value,
            "Address: insufficient balance for call"
        );
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(
        address target,
        bytes memory data,
        uint256 weiValue,
        string memory errorMessage
    ) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{value: weiValue}(
            data
        );
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity 0.6.8;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity 0.6.8;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.0.0, only sets of type `address` (`AddressSet`) and `uint256`
 * (`UintSet`) are supported.
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];

        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;

            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.

            bytes32 lastvalue = set._values[lastIndex];

            // Move the last value to the index where the value to delete is
            set._values[toDeleteIndex] = lastvalue;
            // Update the index for the moved value
            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the index for the deleted slot
            delete set._indexes[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value)
        private
        view
        returns (bool)
    {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function _at(Set storage set, uint256 index)
        private
        view
        returns (bytes32)
    {
        require(
            set._values.length > index,
            "EnumerableSet: index out of bounds"
        );
        return set._values[index];
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value)
        internal
        returns (bool)
    {
        return _add(set._inner, bytes32(uint256(value)));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value)
        internal
        returns (bool)
    {
        return _remove(set._inner, bytes32(uint256(value)));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value)
        internal
        view
        returns (bool)
    {
        return _contains(set._inner, bytes32(uint256(value)));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(AddressSet storage set, uint256 index)
        internal
        view
        returns (address)
    {
        return address(uint256(_at(set._inner, index)));
    }

    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value)
        internal
        returns (bool)
    {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value)
        internal
        view
        returns (bool)
    {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintSet storage set, uint256 index)
        internal
        view
        returns (uint256)
    {
        return uint256(_at(set._inner, index));
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

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

// SPDX-License-Identifier: MIT

pragma solidity 0.6.8;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount)
        external
        returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount)
        external
        returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.2;

import "./IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(
        address indexed from,
        address indexed to,
        uint256 indexed tokenId
    );

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(
        address indexed owner,
        address indexed approved,
        uint256 indexed tokenId
    );

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(
        address indexed owner,
        address indexed operator,
        bool approved
    );

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId)
        external
        view
        returns (address operator);

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator)
        external
        view
        returns (bool);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;
}

// SPDX-License-Identifier: MIT

pragma solidity 0.6.8;

import "./IERC20.sol";

interface IXToken is IERC20 {
    function owner() external returns (address);

    function burn(uint256 amount) external;

    function burnFrom(address account, uint256 amount) external;

    function mint(address to, uint256 amount) external;

    function changeName(string calldata name) external;

    function changeSymbol(string calldata symbol) external;

    function setVaultAddress(address vaultAddress) external;

    function transferOwnership(address newOwner) external;
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.4.24 <0.7.0;

/**
 * @title Initializable
 *
 * @dev Helper contract to support initializer functions. To use it, replace
 * the constructor with a function that has the `initializer` modifier.
 * WARNING: Unlike constructors, initializer functions must be manually
 * invoked. This applies both to deploying an Initializable contract, as well
 * as extending an Initializable contract via inheritance.
 * WARNING: When used with inheritance, manual care must be taken to not invoke
 * a parent initializer twice, or ensure that all initializers are idempotent,
 * because this is not dealt with automatically as with constructors.
 */
contract Initializable {
    /**
   * @dev Indicates that the contract has been initialized.
   */
    bool private initialized;

    /**
   * @dev Indicates that the contract is in the process of being initialized.
   */
    bool private initializing;

    /**
   * @dev Modifier to use in the initializer function of a contract.
   */
    modifier initializer() {
        require(
            initializing || isConstructor() || !initialized,
            "Contract instance has already been initialized"
        );

        bool isTopLevelCall = !initializing;
        if (isTopLevelCall) {
            initializing = true;
            initialized = true;
        }

        _;

        if (isTopLevelCall) {
            initializing = false;
        }
    }

    /// @dev Returns true if and only if the function is running in the constructor
    function isConstructor() private view returns (bool) {
        // extcodesize checks the size of the code stored in an address, and
        // address returns the current address. Since the code is still not
        // deployed when running a constructor, any checks on its code size will
        // yield zero, making it an effective way to detect if a contract is
        // under construction or not.
        address self = address(this);
        uint256 cs;
        assembly {
            cs := extcodesize(self)
        }
        return cs == 0;
    }

    // Reserved storage space to allow for layout changes in the future.
    uint256[50] private ______gap;
}

// SPDX-License-Identifier: MIT

pragma solidity 0.6.8;

import "./Context.sol";
import "./Initializable.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
contract Ownable is Context, Initializable {
    address private _owner;

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function initOwnable() internal virtual initializer {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity 0.6.8;

import "./IERC20.sol";
import "./SafeMath.sol";
import "./Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transfer.selector, to, value)
        );
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value)
        internal
    {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.approve.selector, spender, value)
        );
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value)
        internal
    {
        uint256 newAllowance = token.allowance(address(this), spender).add(
            value
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value)
        internal
    {
        uint256 newAllowance = token.allowance(address(this), spender).sub(
            value,
            "SafeERC20: decreased allowance below zero"
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(
            data,
            "SafeERC20: low-level call failed"
        );
        if (returndata.length > 0) {
            // Return data is optional
            // solhint-disable-next-line max-line-length
            require(
                abi.decode(returndata, (bool)),
                "SafeERC20: ERC20 operation did not succeed"
            );
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity 0.6.8;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage)
        internal
        pure
        returns (uint256)
    {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage)
        internal
        pure
        returns (uint256)
    {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage)
        internal
        pure
        returns (uint256)
    {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity 0.6.8;

import "./EnumerableSet.sol";
import "./Ownable.sol";
import "./SafeMath.sol";
import "./IXToken.sol";
import "./IERC721.sol";
import "./SafeERC20.sol";

contract XStore is Ownable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;
    using EnumerableSet for EnumerableSet.UintSet;

    struct FeeParams {
        uint256 ethBase;
        uint256 ethStep;
    }

    struct BountyParams {
        uint256 ethMax;
        uint256 length;
    }

    struct Vault {
        address xTokenAddress;
        address nftAddress;
        address manager;
        IXToken xToken;
        IERC721 nft;
        EnumerableSet.UintSet holdings;
        EnumerableSet.UintSet reserves;
        mapping(uint256 => address) requester;
        mapping(uint256 => bool) isEligible;
        mapping(uint256 => bool) shouldReserve;
        bool allowMintRequests;
        bool flipEligOnRedeem;
        bool negateEligibility;
        bool isFinalized;
        bool isClosed;
        FeeParams mintFees;
        FeeParams burnFees;
        FeeParams dualFees;
        BountyParams supplierBounty;
        uint256 ethBalance;
        uint256 tokenBalance;
        bool isD2Vault;
        address d2AssetAddress;
        IERC20 d2Asset;
        uint256 d2Holdings;
    }

    event XTokenAddressSet(uint256 indexed vaultId, address token);
    event NftAddressSet(uint256 indexed vaultId, address asset);
    event ManagerSet(uint256 indexed vaultId, address manager);
    event XTokenSet(uint256 indexed vaultId);
    event NftSet(uint256 indexed vaultId);
    event HoldingsAdded(uint256 indexed vaultId, uint256 id);
    event HoldingsRemoved(uint256 indexed vaultId, uint256 id);
    event ReservesAdded(uint256 indexed vaultId, uint256 id);
    event ReservesRemoved(uint256 indexed vaultId, uint256 id);
    event RequesterSet(uint256 indexed vaultId, uint256 id, address requester);
    event IsEligibleSet(uint256 indexed vaultId, uint256 id, bool _bool);
    event ShouldReserveSet(uint256 indexed vaultId, uint256 id, bool _bool);
    event AllowMintRequestsSet(uint256 indexed vaultId, bool isAllowed);
    event FlipEligOnRedeemSet(uint256 indexed vaultId, bool _bool);
    event NegateEligibilitySet(uint256 indexed vaultId, bool _bool);
    event IsFinalizedSet(uint256 indexed vaultId, bool _isFinalized);
    event IsClosedSet(uint256 indexed vaultId, bool _isClosed);
    event MintFeesSet(
        uint256 indexed vaultId,
        uint256 ethBase,
        uint256 ethStep
    );
    event BurnFeesSet(
        uint256 indexed vaultId,
        uint256 ethBase,
        uint256 ethStep
    );
    event DualFeesSet(
        uint256 indexed vaultId,
        uint256 ethBase,
        uint256 ethStep
    );
    event SupplierBountySet(
        uint256 indexed vaultId,
        uint256 ethMax,
        uint256 length
    );
    event EthBalanceSet(uint256 indexed vaultId, uint256 _ethBalance);
    event TokenBalanceSet(uint256 indexed vaultId, uint256 _tokenBalance);
    event IsD2VaultSet(uint256 indexed vaultId, bool _isD2Vault);
    event D2AssetAddressSet(uint256 indexed vaultId, address _d2Asset);
    event D2AssetSet(uint256 indexed vaultId);
    event D2HoldingsSet(uint256 indexed vaultId, uint256 _d2Holdings);
    event NewVaultAdded(uint256 indexed vaultId);
    event IsExtensionSet(address addr, bool _isExtension);
    event RandNonceSet(uint256 _randNonce);

    Vault[] internal vaults;

    mapping(address => bool) public isExtension;
    uint256 public randNonce;

    constructor() public {
        initOwnable();
    }

    function _getVault(uint256 vaultId) internal view returns (Vault storage) {
        require(vaultId < vaults.length, "Invalid vaultId");
        return vaults[vaultId];
    }

    function vaultsLength() public view returns (uint256) {
        return vaults.length;
    }

    function xTokenAddress(uint256 vaultId) public view returns (address) {
        Vault storage vault = _getVault(vaultId);
        return vault.xTokenAddress;
    }

    function nftAddress(uint256 vaultId) public view returns (address) {
        Vault storage vault = _getVault(vaultId);
        return vault.nftAddress;
    }

    function manager(uint256 vaultId) public view returns (address) {
        Vault storage vault = _getVault(vaultId);
        return vault.manager;
    }

    function xToken(uint256 vaultId) public view returns (IXToken) {
        Vault storage vault = _getVault(vaultId);
        return vault.xToken;
    }

    function nft(uint256 vaultId) public view returns (IERC721) {
        Vault storage vault = _getVault(vaultId);
        return vault.nft;
    }

    function holdingsLength(uint256 vaultId) public view returns (uint256) {
        Vault storage vault = _getVault(vaultId);
        return vault.holdings.length();
    }

    function holdingsContains(uint256 vaultId, uint256 elem)
        public
        view
        returns (bool)
    {
        Vault storage vault = _getVault(vaultId);
        return vault.holdings.contains(elem);
    }

    function holdingsAt(uint256 vaultId, uint256 index)
        public
        view
        returns (uint256)
    {
        Vault storage vault = _getVault(vaultId);
        return vault.holdings.at(index);
    }

    function reservesLength(uint256 vaultId) public view returns (uint256) {
        Vault storage vault = _getVault(vaultId);
        return vault.holdings.length();
    }

    function reservesContains(uint256 vaultId, uint256 elem)
        public
        view
        returns (bool)
    {
        Vault storage vault = _getVault(vaultId);
        return vault.holdings.contains(elem);
    }

    function reservesAt(uint256 vaultId, uint256 index)
        public
        view
        returns (uint256)
    {
        Vault storage vault = _getVault(vaultId);
        return vault.holdings.at(index);
    }

    function requester(uint256 vaultId, uint256 id)
        public
        view
        returns (address)
    {
        Vault storage vault = _getVault(vaultId);
        return vault.requester[id];
    }

    function isEligible(uint256 vaultId, uint256 id)
        public
        view
        returns (bool)
    {
        Vault storage vault = _getVault(vaultId);
        return vault.isEligible[id];
    }

    function shouldReserve(uint256 vaultId, uint256 id)
        public
        view
        returns (bool)
    {
        Vault storage vault = _getVault(vaultId);
        return vault.shouldReserve[id];
    }

    function allowMintRequests(uint256 vaultId) public view returns (bool) {
        Vault storage vault = _getVault(vaultId);
        return vault.allowMintRequests;
    }

    function flipEligOnRedeem(uint256 vaultId) public view returns (bool) {
        Vault storage vault = _getVault(vaultId);
        return vault.flipEligOnRedeem;
    }

    function negateEligibility(uint256 vaultId) public view returns (bool) {
        Vault storage vault = _getVault(vaultId);
        return vault.negateEligibility;
    }

    function isFinalized(uint256 vaultId) public view returns (bool) {
        Vault storage vault = _getVault(vaultId);
        return vault.isFinalized;
    }

    function isClosed(uint256 vaultId) public view returns (bool) {
        Vault storage vault = _getVault(vaultId);
        return vault.isClosed;
    }

    function mintFees(uint256 vaultId) public view returns (uint256, uint256) {
        Vault storage vault = _getVault(vaultId);
        return (vault.mintFees.ethBase, vault.mintFees.ethStep);
    }

    function burnFees(uint256 vaultId) public view returns (uint256, uint256) {
        Vault storage vault = _getVault(vaultId);
        return (vault.burnFees.ethBase, vault.burnFees.ethStep);
    }

    function dualFees(uint256 vaultId) public view returns (uint256, uint256) {
        Vault storage vault = _getVault(vaultId);
        return (vault.dualFees.ethBase, vault.dualFees.ethStep);
    }

    function supplierBounty(uint256 vaultId)
        public
        view
        returns (uint256, uint256)
    {
        Vault storage vault = _getVault(vaultId);
        return (vault.supplierBounty.ethMax, vault.supplierBounty.length);
    }

    function ethBalance(uint256 vaultId) public view returns (uint256) {
        Vault storage vault = _getVault(vaultId);
        return vault.ethBalance;
    }

    function tokenBalance(uint256 vaultId) public view returns (uint256) {
        Vault storage vault = _getVault(vaultId);
        return vault.tokenBalance;
    }

    function isD2Vault(uint256 vaultId) public view returns (bool) {
        Vault storage vault = _getVault(vaultId);
        return vault.isD2Vault;
    }

    function d2AssetAddress(uint256 vaultId) public view returns (address) {
        Vault storage vault = _getVault(vaultId);
        return vault.d2AssetAddress;
    }

    function d2Asset(uint256 vaultId) public view returns (IERC20) {
        Vault storage vault = _getVault(vaultId);
        return vault.d2Asset;
    }

    function d2Holdings(uint256 vaultId) public view returns (uint256) {
        Vault storage vault = _getVault(vaultId);
        return vault.d2Holdings;
    }

    function setXTokenAddress(uint256 vaultId, address _xTokenAddress)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.xTokenAddress = _xTokenAddress;
        emit XTokenAddressSet(vaultId, _xTokenAddress);
    }

    function setNftAddress(uint256 vaultId, address _nft) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.nftAddress = _nft;
        emit NftAddressSet(vaultId, _nft);
    }

    function setManager(uint256 vaultId, address _manager) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.manager = _manager;
        emit ManagerSet(vaultId, _manager);
    }

    function setXToken(uint256 vaultId) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.xToken = IXToken(vault.xTokenAddress);
        emit XTokenSet(vaultId);
    }

    function setNft(uint256 vaultId) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.nft = IERC721(vault.nftAddress);
        emit NftSet(vaultId);
    }

    function holdingsAdd(uint256 vaultId, uint256 elem) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.holdings.add(elem);
        emit HoldingsAdded(vaultId, elem);
    }

    function holdingsRemove(uint256 vaultId, uint256 elem) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.holdings.remove(elem);
        emit HoldingsRemoved(vaultId, elem);
    }

    function reservesAdd(uint256 vaultId, uint256 elem) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.reserves.add(elem);
        emit ReservesAdded(vaultId, elem);
    }

    function reservesRemove(uint256 vaultId, uint256 elem) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.reserves.remove(elem);
        emit ReservesRemoved(vaultId, elem);
    }

    function setRequester(uint256 vaultId, uint256 id, address _requester)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.requester[id] = _requester;
        emit RequesterSet(vaultId, id, _requester);
    }

    function setIsEligible(uint256 vaultId, uint256 id, bool _bool)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.isEligible[id] = _bool;
        emit IsEligibleSet(vaultId, id, _bool);
    }

    function setShouldReserve(uint256 vaultId, uint256 id, bool _shouldReserve)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.shouldReserve[id] = _shouldReserve;
        emit ShouldReserveSet(vaultId, id, _shouldReserve);
    }

    function setAllowMintRequests(uint256 vaultId, bool isAllowed)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.allowMintRequests = isAllowed;
        emit AllowMintRequestsSet(vaultId, isAllowed);
    }

    function setFlipEligOnRedeem(uint256 vaultId, bool flipElig)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.flipEligOnRedeem = flipElig;
        emit FlipEligOnRedeemSet(vaultId, flipElig);
    }

    function setNegateEligibility(uint256 vaultId, bool negateElig)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.negateEligibility = negateElig;
        emit NegateEligibilitySet(vaultId, negateElig);
    }

    function setIsFinalized(uint256 vaultId, bool _isFinalized)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.isFinalized = _isFinalized;
        emit IsFinalizedSet(vaultId, _isFinalized);
    }

    function setIsClosed(uint256 vaultId, bool _isClosed) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.isClosed = _isClosed;
        emit IsClosedSet(vaultId, _isClosed);
    }

    function setMintFees(uint256 vaultId, uint256 ethBase, uint256 ethStep)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.mintFees = FeeParams(ethBase, ethStep);
        emit MintFeesSet(vaultId, ethBase, ethStep);
    }

    function setBurnFees(uint256 vaultId, uint256 ethBase, uint256 ethStep)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.burnFees = FeeParams(ethBase, ethStep);
        emit BurnFeesSet(vaultId, ethBase, ethStep);
    }

    function setDualFees(uint256 vaultId, uint256 ethBase, uint256 ethStep)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.dualFees = FeeParams(ethBase, ethStep);
        emit DualFeesSet(vaultId, ethBase, ethStep);
    }

    function setSupplierBounty(uint256 vaultId, uint256 ethMax, uint256 length)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.supplierBounty = BountyParams(ethMax, length);
        emit SupplierBountySet(vaultId, ethMax, length);
    }

    function setEthBalance(uint256 vaultId, uint256 _ethBalance)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.ethBalance = _ethBalance;
        emit EthBalanceSet(vaultId, _ethBalance);
    }

    function setTokenBalance(uint256 vaultId, uint256 _tokenBalance)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.tokenBalance = _tokenBalance;
        emit TokenBalanceSet(vaultId, _tokenBalance);
    }

    function setIsD2Vault(uint256 vaultId, bool _isD2Vault) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.isD2Vault = _isD2Vault;
        emit IsD2VaultSet(vaultId, _isD2Vault);
    }

    function setD2AssetAddress(uint256 vaultId, address _d2Asset)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.d2AssetAddress = _d2Asset;
        emit D2AssetAddressSet(vaultId, _d2Asset);
    }

    function setD2Asset(uint256 vaultId) public onlyOwner {
        Vault storage vault = _getVault(vaultId);
        vault.d2Asset = IERC20(vault.d2AssetAddress);
        emit D2AssetSet(vaultId);
    }

    function setD2Holdings(uint256 vaultId, uint256 _d2Holdings)
        public
        onlyOwner
    {
        Vault storage vault = _getVault(vaultId);
        vault.d2Holdings = _d2Holdings;
        emit D2HoldingsSet(vaultId, _d2Holdings);
    }

    ////////////////////////////////////////////////////////////

    function addNewVault() public onlyOwner returns (uint256) {
        Vault memory newVault;
        vaults.push(newVault);
        uint256 vaultId = vaults.length.sub(1);
        emit NewVaultAdded(vaultId);
        return vaultId;
    }

    function setIsExtension(address addr, bool _isExtension) public onlyOwner {
        isExtension[addr] = _isExtension;
        emit IsExtensionSet(addr, _isExtension);
    }

    function setRandNonce(uint256 _randNonce) public onlyOwner {
        randNonce = _randNonce;
        emit RandNonceSet(_randNonce);
    }
}

{
  "compilationTarget": {
    "XStore.sol": "XStore"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}