@Override
        public Object answer() throws Throwable {
          Object[] args = getCurrentArguments();
          attributeMap.put((String) args[0], args[1]);
          return null;
        }
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