@Test
public void startOnce() {

    List<Throwable> error = TestHelper.trackPluginErrors();
    try {
        TestDisposableSubscriber<Integer> tc = new TestDisposableSubscriber<Integer>();
        tc.onSubscribe(new BooleanSubscription());
        BooleanSubscription d = new BooleanSubscription();
        tc.onSubscribe(d);
        assertTrue(d.isCancelled());
        assertEquals(1, tc.start);
        TestHelper.assertError(error, 0, IllegalStateException.class, EndConsumerHelper.composeMessage(tc.getClass().getName()));
    } finally {
        RxJavaPlugins.reset();
    }
}