src/main/java/io/reactivex/internal/operators/observable/ObservableReplay.java
public static <T> ConnectableObservable<T> observeOn(final ConnectableObservable<T> co, final Scheduler scheduler) {
        final Observable<T> observable = co.observeOn(scheduler);
        return RxJavaPlugins.onAssembly(new Replay<T>(co, observable));
    }
public static <T> ConnectableObservable<T> observeOn(final ConnectableObservable<T> co, final Scheduler scheduler) {
        final Observable<T> observable = co.observeOn(scheduler);
        return RxJavaPlugins.onAssembly(new Replay<T>(co, observable));
    }
Child Observers will observe the events of the ConnectableObservable on the
specified scheduler.
@param <T> the value type
@param co the connectable observable instance
@param scheduler the target scheduler
@return the new ConnectableObservable instance