EnumerableSet

function _add(Set storage set, bytes32 value) private returns (bool);

function _remove(Set storage set, bytes32 value) private returns (bool);

function _contains(Set storage set, bytes32 value) private view returns (bool);

function _length(Set storage set) private view returns (uint256);

function _at(Set storage set, uint256 index) private view returns (bytes32);

function _values(Set storage set) private view returns (bytes32[] memory);

function add(Bytes32Set storage set, bytes32 value) internal returns (bool);

function remove(Bytes32Set storage set, bytes32 value) internal returns (bool);

function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool);

function length(Bytes32Set storage set) internal view returns (uint256);

function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32);

function values(Bytes32Set storage set) internal view returns (bytes32[] memory);

function add(AddressSet storage set, address value) internal returns (bool);

function remove(AddressSet storage set, address value) internal returns (bool);

function contains(AddressSet storage set, address value) internal view returns (bool);

function length(AddressSet storage set) internal view returns (uint256);

function at(AddressSet storage set, uint256 index) internal view returns (address);

function values(AddressSet storage set) internal view returns (address[] memory result);

function add(UintSet storage set, uint256 value) internal returns (bool);

function remove(UintSet storage set, uint256 value) internal returns (bool);

function contains(UintSet storage set, uint256 value) internal view returns (bool);

function length(UintSet storage set) internal view returns (uint256);

function at(UintSet storage set, uint256 index) internal view returns (uint256);

function values(UintSet storage set) internal view returns (uint256[] memory result);

function add(Bytes4Set storage set, bytes4 value) internal returns (bool);

function remove(Bytes4Set storage set, bytes4 value) internal returns (bool);

function contains(Bytes4Set storage set, bytes4 value) internal view returns (bool);

function length(Bytes4Set storage set) internal view returns (uint256);

function at(Bytes4Set storage set, uint256 index) internal view returns (bytes4);

function values(Bytes4Set storage set) internal view returns (bytes4[] memory result);

struct Set {
        bytes32[] _values;
        mapping(bytes32 value => uint256 position) _positions; // 1-based; 0 = absent
    }

struct AddressSet {
        Set _inner;
    }

struct Bytes32Set {
        Set _inner;
    }

struct UintSet {
        Set _inner;
    }

struct Bytes4Set {
        bytes4[] _values;
        mapping(bytes4 value => uint256 position) _positions;
    }