ERC20Locker used to be compiled with Solidity 0.6.12, so it needed to use SafeMath dependency. Currently, the contract code base utilizes Solidity 0.8.x, which has built in support of overflow and underflow warnings. Thus SafeMath library can be omitted for gas savings and code simplification.
ERC20Lockerused to be compiled with Solidity 0.6.12, so it needed to useSafeMathdependency. Currently, the contract code base utilizes Solidity 0.8.x, which has built in support of overflow and underflow warnings. Thus SafeMath library can be omitted for gas savings and code simplification.