src/main/java/io/reactivex/observables/ConnectableObservable.java
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Observable<T> refCount(int subscriberCount) {
        return refCount(subscriberCount, 0, TimeUnit.NANOSECONDS, Schedulers.trampoline());
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Observable<T> refCount(int subscriberCount) {
        return refCount(subscriberCount, 0, TimeUnit.NANOSECONDS, Schedulers.trampoline());
    }
@ CheckReturnValue @ SchedulerSupport ( SchedulerSupport . NONE ) public final Observable < T > refCount ( int subscriberCount ) { return refCount ( subscriberCount , 0 , TimeUnit . NANOSECONDS , Schedulers . trampoline ( ) ) ; }
Connects to the upstream {@code ConnectableObservable} if the number of subscribed
subscriber reaches the specified count and disconnect if all subscribers have unsubscribed.
<dl>
<dt><b>Scheduler:</b></dt>
<dd>This {@code refCount} overload does not operate on any particular {@link Scheduler}.</dd>
</dl>
<p>History: 2.1.14 - experimental
@param subscriberCount the number of subscribers required to connect to the upstream
@return the new Observable instance
@since 2.2
Connects to the upstream {