@SuppressWarnings("unchecked")
@Test
public void from() {

    TestSubscriber<Integer> ts = new TestSubscriber<Integer>();
    ParallelFlowable.fromArray(Flowable.range(1, 5), Flowable.range(6, 5))
    .sequential()
    .subscribe(ts);
    ts.assertValueSet(new HashSet<Integer>(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)))
    .assertNoErrors()
    .assertComplete();
}