import { type ObservedValueUnionFromArray } from "https://deno.land/x/rxjs@v1.0.2/mod.ts";
Extracts a union of element types from an ObservableInput<any>[].
If you have O extends ObservableInput<any>[] and you pass in
Observable<string>[] or Promise<string>[] you would get
back a type of string.
If you pass in [Observable<string>, Observable<number>] you would
get back a type of string | number.
definition: X extends Array<ObservableInput<infer T>> ? T : never