private static String buildDefaultStreamPropertiesPrefix(String systemName) {
    return String.format(SystemConfig.SYSTEM_DEFAULT_STREAMS_PREFIX_FORMAT, 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