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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _process_incoming_message(self, stanza_obj):
 """ Process an incoming message stanza `stanza_obj`. """

        self._logger.debug("incoming message: %r", stanza_obj)

        stanza_obj = self.service_inbound_message_filter.filter(stanza_obj)
        if stanza_obj is None:
            self._logger.debug("incoming message dropped by service "
                               "filter chain")
            return

        stanza_obj = self.app_inbound_message_filter.filter(stanza_obj)
        if stanza_obj is None:
            self._logger.debug("incoming message dropped by application "
                               "filter chain")
            return

        self.on_message_received(stanza_obj)