public boolean isTimeoutException() {
        return internalException instanceof TimeoutException;
    }
@Test
    public void testIsNotTimeoutException() {
        assertFalse(TOPIC_EXISTS.isTimeoutException());
        assertFalse(REJECTED_EXECUTION.isTimeoutException());
        assertFalse(INTERRUPTED.isTimeoutException());
        assertFalse(NULL_POINTER.isTimeoutException());
        assertFalse(NOT_LEADER.isTimeoutException());
    }