@Override
    public SystemAdmin getAdmin(String systemName, Config config) {
      switch (systemName) {
        case MOCK_SYSTEM_NAME1:
          return SYSTEM_ADMIN1;
        case MOCK_SYSTEM_NAME2:
          return SYSTEM_ADMIN2;
        default:
          throw new UnsupportedOperationException("System name unsupported: " + systemName);
      }
    }
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