code: def _serializeExtraData(self, extraDataDir):
      
      makeDirectoryFromAbsolutePath(extraDataDir)
  
      #--------------------------------------------------
      # Save the network
      outputDir = self.__getNetworkStateDirectory(extraDataDir=extraDataDir)
  
      self.__logger.debug("Serializing network...")
  
      self._netInfo.net.save(outputDir)
  
      self.__logger.debug("Finished serializing network")
  
      return
docs: [virtual method override] This method is called during serialization
      with an external directory path that can be used to bypass pickle for saving
      large binary states.
  
      extraDataDir:
                    Model's extra data directory path