Module diff_ser 

Any changes to state during the simulation tick are recorded by this system as they’re happening. Rollback and rx systems use this data to make multiplayer happen

Structs

DiffSerializer

All state-mutating function signatures that the code generator produces require this struct to be passed in. It follows the opaque handle pattern, so everything Just Works™. Internally, it’s capturing and serializing the before and after values, allowing the value to be both rolled back and transmitted to clients.