SafeMath :
Wrappers over Solidity's arithmetic operations. NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler now has built in overflow checking.
Clones :
https://eips.ethereum.org/EIPS/eip-1167[EIP 1167] is a standard for deploying minimal proxy contracts, also known as "clones". > To simply and cheaply clone contract functionality in an immutable way, this standard specifies > a minimal bytecode implementation that delegates all calls to a known, fixed address. The library includes functions to deploy a proxy using either `create` (traditional deployment) or `create2` (salted deterministic deployment). It also includes functions to predict the addresses of clones deployed using the deterministic method. _Available since v3.4._
Address :
Collection of functions related to the address type