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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:
 async def _on_message(self, update):
 """Receive a message from a service."""


        name = update['service']
        message_obj = update['payload']

        if name not in self.services:
            return

        with self._state_lock:
            self.services[name].post_message(message_obj['level'], message_obj['message'])