src/main/java/io/reactivex/Flowable.java
@CheckReturnValue
    @BackpressureSupport(BackpressureKind.FULL)
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Flowable<T> repeat() {
        return repeat(Long.MAX_VALUE);
    }
@CheckReturnValue
    @BackpressureSupport(BackpressureKind.FULL)
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Flowable<T> repeat() {
        return repeat(Long.MAX_VALUE);
    }
Returns a Flowable that repeats the sequence of items emitted by the source Publisher indefinitely.
<p>
<img width="640" height="309" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/repeat.o.png" alt="">
<dl>
<dt><b>Backpressure:</b></dt>
<dd>The operator honors downstream backpressure and expects the source {@code Publisher} to honor backpressure as well.
If this expectation is violated, the operator <em>may</em> throw an {@code IllegalStateException}.</dd>
<dt><b>Scheduler:</b></dt>
<dd>{@code repeat} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>

@return a Flowable that emits the items emitted by the source Publisher repeatedly and in sequence
@see <a href="http://reactivex.io/documentation/operators/repeat.html">ReactiveX operators documentation: Repeat</a>