@Test(expected = IllegalArgumentException.class)
 public void testRemoveNonPresentMessageTTL() {
   _metadataRepo.remove(new UOID());
   fail("Unexpected absence of IllegalArgumentException");
 }
 @Test
 public void testRemoveAvailableMessage() {
   _metadataRepo.remove(AVAILABLE_ID);
   assertFalse("Checking availablity after remove", _metadataRepo.containsMetricTTL(AVAILABLE_ID));
 }