code: public static synchronized PortRange getUdpSourceInstance() {
          if (udpSourcePortRange == null) {
              udpSourcePortRange = new PortRange();
              udpSourcePortRange.init(
                    CoGProperties.getDefault().getUdpSourcePortRange());
          }
          return udpSourcePortRange;
      }
docs: Returns PortRange instance for UDP source sockets.
  If the udp.source.port.range property is set, the class
  will be initialized with the specified port ranges.
  
  @return PortRange the default instace of this class.