src/main/java/io/reactivex/flowables/ConnectableFlowable.java
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.COMPUTATION)
    @BackpressureSupport(BackpressureKind.PASS_THROUGH)
    public final Flowable<T> refCount(long timeout, TimeUnit unit) {
        return refCount(1, timeout, unit, Schedulers.computation());
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.COMPUTATION)
    @BackpressureSupport(BackpressureKind.PASS_THROUGH)
    public final Flowable<T> refCount(long timeout, TimeUnit unit) {
        return refCount(1, timeout, unit, Schedulers.computation());
    }
Connects to the upstream {@code ConnectableFlowable} if the number of subscribed
subscriber reaches 1 and disconnect after the specified
timeout if all subscribers have unsubscribed.
<dl>
<dt><b>Backpressure:</b></dt>
<dd>The operator itself doesn't interfere with backpressure which is determined by the upstream
{@code ConnectableFlowable}'s backpressure behavior.</dd>
<dt><b>Scheduler:</b></dt>
<dd>This {@code refCount} overload operates on the {@code computation} {@link Scheduler}.</dd>
</dl>
<p>History: 2.1.14 - experimental
@param timeout the time to wait before disconnecting after all subscribers unsubscribed
@param unit the time unit of the timeout
@return the new Flowable instance
@see #refCount(long, TimeUnit, Scheduler)
@since 2.2