Combines the source Observable with other Observables to create an Observable whose values are calculated from the latest values of each, only when the source emits.
--a-----b-------c---d---e--withLatestFrom(-----1----2-3-4------------)--------b1------c4--d4--e4- Copy
--a-----b-------c---d---e--withLatestFrom(-----1----2-3-4------------)--------b1------c4--d4--e4-
Combines the source Observable with other Observables to create an Observable whose values are calculated from the latest values of each, only when the source emits.