struct LockUp {
 uint256 lockupAmount,
 uint256 startTime,
 uint256 lockUpPeriodSeconds,
 uint256 releaseFrequencySeconds
}

//public members
mapping(bytes32 => struct LockUpTransferManagerStorage.LockUp) public lockups;
​
//internal members
mapping(address => bytes32[]) internal userToLockups;
mapping(bytes32 => address[]) internal lockupToUsers;
mapping(address => mapping(bytes32 => uint256)) internal userToLockupIndex;
mapping(bytes32 => mapping(address => uint256)) internal lockupToUserIndex;
bytes32[] internal lockupArray;