Close channels and underlying pubsub handler

        :return: a coroutine and therefore it must be awaited

async def close(self):
        """Close channels and underlying pubsub handler

        :return: a coroutine and therefore it must be awaited
        """
        push_connection = self.pubsub.push_connection
        self.status = self.statusType.closed
        if push_connection:
            push_connection.event('connection_lost').unbind(
                self._connection_lost
            )
            await self.pubsub.close()