private ServiceComponentHost createMockServiceComponentHost(State state) {
    ServiceComponentHost serviceComponentHost = createMock(ServiceComponentHost.class);
    expect(serviceComponentHost.getDesiredState()).andReturn(state).anyTimes();
    return serviceComponentHost;
  }
Test that a Kerberos Descriptor that contains a Service with 0 Components does not raise any exceptions.
ambari-server/src/test/java/org/apache/ambari/server/controller/KerberosHelperTest.java