What kind of special call can a contract make to another contract that stops both contracts from changing their saved data during that call?

The special call a contract can make to another contract that stops both contracts from changing their saved data during that call is called a `STATICCALL`. A `STATICCALL` is a specific type of message call opcode within the Ethereum Virtual Machine, which is the runtime environment where smart contracts execute. It is fundamentally designed to be read-only, meaning it strictly enforces that no state modifications can occur throughout its execution. "Saved data" refers to a contract's "state variabl....