code: protected String getRPCPortRange(Configuration configuration) {
  		if (ZooKeeperUtils.isZooKeeperRecoveryMode(configuration)) {
  			return configuration.getString(HighAvailabilityOptions.HA_JOB_MANAGER_PORT_RANGE);
  		} else {
  			return String.valueOf(configuration.getInteger(JobManagerOptions.PORT));
  		}
  	}
docs: Returns the port range for the common {@link RpcService}.
  
  @param configuration to extract the port range from
  @return Port range for the common {@link RpcService}