default SystemConsumer getConsumer(String systemName, Config config, MetricsRegistry registry, String consumerLabel) {
    return getConsumer(systemName, config, registry);
  }
This function provides an extra input parameter to {@link #getConsumer}, which can be used to provide extra
information for the consumer instance, e.g. ownership of client instance, to help better identify consumers in logs,
threads and client instances etc., along with other relevant information like systemName.

@param systemName The name of the system to create consumer for.
@param config The config to create consumer with.
@param registry MetricsRegistry to which to publish consumer specific metrics.
@param consumerLabel a string to provide info the consumer instance.
@return A SystemConsumer
samza-api/src/main/java/org/apache/samza/system/SystemFactory.java