import { type ObservedValueTupleFromArray } from "https://deno.land/x/rxjs@v1.0.2/mod.ts";
Extracts a tuple of element types from an ObservableInput<any>[].
If you have O extends ObservableInput<any>[] and you pass in
[Observable<string>, Observable<number>] you would get back a type
of [string, number].
definition: [K in keyof X]: ObservedValueOf<X[K]>