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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 unsubscribe(self, topics):
 """ Unsubscribe from some topics. Send a MQTT `UNSUBSCRIBE <http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718072>`_ message and wait for broker `UNSUBACK <http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718077>`_ message. This method is a *coroutine*. :param topics: array of topics to unsubscribe from. Example of ``topics`` argument expected structure: :: ['$SYS/broker/uptime', '$SYS/broker/load/#'] """

        yield from self._handler.mqtt_unsubscribe(topics, self.session.next_packet_id)