src/main/java/io/reactivex/Observable.java
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final <U> Observable<T> delaySubscription(ObservableSource<U> other) {
        ObjectHelper.requireNonNull(other, "other is null");
        return RxJavaPlugins.onAssembly(new ObservableDelaySubscriptionOther<T, U>(this, other));
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final <U> Observable<T> delaySubscription(ObservableSource<U> other) {
        ObjectHelper.requireNonNull(other, "other is null");
        return RxJavaPlugins.onAssembly(new ObservableDelaySubscriptionOther<T, U>(this, other));
    }
@ CheckReturnValue @ SchedulerSupport ( SchedulerSupport . NONE ) public final < U > Observable < T > delaySubscription ( ObservableSource < U > other ) { ObjectHelper . requireNonNull ( other , "other is null" ) ; return RxJavaPlugins . onAssembly ( new ObservableDelaySubscriptionOther < T , U > ( this , other ) ) ; }
Returns an Observable that delays the subscription to this Observable
until the other Observable emits an element or completes normally.
<p>
<img width="640" height="310" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/delaySubscription.o.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>This method does not operate by default on a particular {@link Scheduler}.</dd>
</dl>

@param <U> the value type of the other Observable, irrelevant
@param other the other Observable that should trigger the subscription
to this Observable.
@return an Observable that delays the subscription to this Observable
until the other Observable emits an element or completes normally.
@since 2.0
Returns an Observable that delays the subscription to this Observable until the other Observable emits an element or completes normally . <p > <img width = 640 height = 310 src = https : // raw . github . com / wiki / ReactiveX / RxJava / images / rx - operators / delaySubscription . o . png alt = > <dl > <dt > <b > Scheduler : < / b > < / dt > <dd > This method does not operate by default on a particular { @link Scheduler } . < / dd > < / dl >