diffOf
Returns a Diff of previous and current values of the supplied input.
Note: while this method is not a hook, it exhibits one important similarity in that it must be called unconditionally in order to ensure correctness across multiple invocations.
Return
A Diff of previous and current values of the supplied input.
Parameters
input
The input value whose diff is to be calculated. This input must have already been defined as a dependency of the useTransition call.