@Test
public void testNotifyStatistics_send_successfulForMail() {

    NotifyStatistics statistics = channelChainTestObject.send(subscriber, eventTOs);
    assertEquals(0, statistics.getFailedCounter());
    assertEquals(2, statistics.getDeliveredCounter()); // 2 since 2 channels
    assertEquals(2, statistics.getTotalCounter()); // 2 since 2 channels
}