@Override
    public SystemProducer getProducer(String systemName, Config config, MetricsRegistry registry) {
      throw new UnsupportedOperationException("Unnecessary for test");
    }
Placeholder to help make sure the correct {@link SystemAdmin} is returned by {@link MockSystemFactory}. Do not mock
any methods of this mock.
samza-core/src/test/java/org/apache/samza/config/TestSystemConfig.java