@Test
public void checkDoubleDefaultSubscriberNonAnonymous() {

    Subscriber<Integer> consumer = new EndDefaultSubscriber();
    BooleanSubscription sub1 = new BooleanSubscription();
    consumer.onSubscribe(sub1);
    assertFalse(sub1.isCancelled());
    BooleanSubscription sub2 = new BooleanSubscription();
    consumer.onSubscribe(sub2);
    assertFalse(sub1.isCancelled());
    assertTrue(sub2.isCancelled());
    TestHelper.assertError(errors, 0, ProtocolViolationException.class);
    // with this consumer, the class name should be predictable
    assertEquals(EndConsumerHelper.composeMessage("io.reactivex.internal.util.EndConsumerHelperTest$EndDefaultSubscriber"), errors.get(0).getMessage());
    assertEquals(errors.toString(), 1, errors.size());
}