interface IERC20PermitAllowed {
    /// @notice Approve the spender to spend some tokens via the holder signature
    /// @dev This is the permit interface used by DAI and CHAI
    /// @param holder The address of the token holder, the token owner
    /// @param spender The address of the token spender
    /// @param nonce The holder's nonce, increases at each call to permit
    /// @param expiry The timestamp at which the permit is no longer valid
    /// @param allowed Boolean that sets approval amount, true for type(uint256).max and false for 0
    /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
    /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
    /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
    function permit(
        address holder,
        address spender,
        uint256 nonce,
        uint256 expiry,
        bool allowed,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
}
/// @title Interface for permit
/// @notice Interface used by DAI/CHAI for permit
function permit(
    address holder,
    address spender,
    uint256 nonce,
    uint256 expiry,
    bool allowed,
    uint8 v,
    bytes32 r,
    bytes32 s
) external;

/// @notice Approve the spender to spend some tokens via the holder signature
/// @dev This is the permit interface used by DAI and CHAI
/// @param holder The address of the token holder, the token owner
/// @param spender The address of the token spender
/// @param nonce The holder's nonce, increases at each call to permit
/// @param expiry The timestamp at which the permit is no longer valid
/// @param allowed Boolean that sets approval amount, true for type(uint256).max and false for 0
/// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
/// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
/// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`