public Config getDefaultStreamProperties(String systemName) {
    return subset(String.format(SYSTEM_DEFAULT_STREAMS_PREFIX_FORMAT, systemName), true);
  }
Gets the system-wide defaults for streams.

@param systemName the name of the system for which the defaults will be returned.
@return a subset of the config with the system prefix removed.
samza-core/src/main/java/org/apache/samza/config/SystemConfig.java