code: def process_message(self, stanza):
          
  
          stanza_type = stanza.stanza_type
          if stanza_type is None:
              stanza_type = "normal"
  
          if self.__try_handlers(self._message_handlers, stanza,
                                                  stanza_type = stanza_type):
              return True
  
          if stanza_type not in ("error", "normal"):
              # try 'normal' handler additionaly to the regular handler
              return self.__try_handlers(self._message_handlers, stanza,
                                                      stanza_type = "normal")
          return False
docs: Process message stanza.
  
          Pass it to a handler of the stanza's type and payload namespace.
          If no handler for the actual stanza type succeeds then hadlers
          for type "normal" are used.
  
          :Parameters:
              - `stanza`: message stanza to be handled