@Test
  public void testReplicaTypeNotFound() throws Exception {
    NetworkClient compositeClient =
        new CompositeNetworkClient(new EnumMap<>(Collections.singletonMap(ReplicaType.DISK_BACKED, diskMocks.client)));
    TestUtils.assertException(IllegalStateException.class,
        () -> compositeClient.sendAndPoll(Collections.singletonList(getRequestInfo(ReplicaType.CLOUD_BACKED)),
            Collections.emptySet(), 1000), null);
  }
Test when a child client is not configured for a type of replica
ambry-network/src/test/java/com/github/ambry/network/CompositeNetworkClientTest.java