docs: def handle_message(self, msg, host):
          """Processes messages that have been delivered from the listener.
  
          Args:
            msg (string): The raw packet data delivered from the listener. This
              data will be unserialized and then processed based on the packet's
              method.
            host (tuple): The (address, host) tuple of the source message.
  
          Returns:
            A response that will be sent back to the client via the listener.
  
          """
  
          response = None
  
          # Unserialize the packet, and decrypt if the host has encryption enabled
          if host in self.encrypted_hosts:
              msg_data = unserialize_data(msg, self.compression, self.encryption)
          else:
              msg_data = unserialize_data(msg, self.compression)
  
          logger.debug("Packet received: " + pformat(msg_data))
  
          # If the message data is blank, return none
          if not msg_data: return response
  
          # For debug purposes, check if the client is registered or not
          if self.is_registered(msg_data["cuuid"], host[0]):
              logger.debug("<%s> Client is currently registered" % msg_data["cuuid"])
          else:
              logger.debug("<%s> Client is not registered"  % msg_data["cuuid"])
  
          if "method" in msg_data:
              if msg_data["method"] == "REGISTER":
                  logger.debug("<%s> Register packet received" % msg_data["cuuid"])
                  response = self.register(msg_data, host)
  
              elif msg_data["method"] == "OHAI":
                  if not self.discoverable:
                      return False
                  logger.debug("<%s> Autodiscover packet received" % msg_data["cuuid"])
                  response = self.autodiscover(msg_data)
  
              elif msg_data["method"] == "AUTH":
                  logger.debug("<%s> Authentication packet recieved" % msg_data["cuuid"])
                  response = self.auth_server.verify_login(msg_data)
                  if response:
                      self.registry[host]["authenticated"] = True
  
              else:
                  if self.auth_server:
                      if self.registry[host]["authenticated"]:
                          response = self.handle_message_registered(msg_data, host)
                  else:
                      response = self.handle_message_registered(msg_data, host)
  
          logger.debug("Packet processing completed")
          return response