@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final <U, R> Observable<R> zipWith(ObservableSource<? extends U> other,
            BiFunction<? super T, ? super U, ? extends R> zipper, boolean delayError) {
        return zip(this, other, zipper, delayError);
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final <U, R> Observable<R> zipWith(ObservableSource<? extends U> other,
            BiFunction<? super T, ? super U, ? extends R> zipper, boolean delayError) {
        return zip(this, other, zipper, delayError);
    }
@checkreturnvalue @schedulersupport(schedulersupport.none) public final <u, r> observable<r> zipwith(observablesource<? extends u> other, bifunction<? super t, ? super u, ? extends r> zipper, boolean delayerror) { return zip(this, other, zipper, delayerror); }