@Test
public void testMetrics_sendConfirmation_OnceSuccessful_OnceUnsuccessful() {

    setNewMetrics();
    boolean isSent = confirmationServiceImpl.sendConfirmation(confirmationInfoMock_sent);
    assertTrue("send confirmation should be successful", isSent);
    confirmationServiceImpl.sendConfirmation(confirmationInfoMock_notSent);
    double successRate = getSuccessRate();
    assertEquals(0.5, successRate, 0);
    assertEquals(2, getAllSent());
    assertEquals(1, getSentFailed());
}