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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, channel):
 """ Remove the channel from this socket's channels, and from the list of subscribed session IDs for the channel. Return False if not subscribed, otherwise True. """

        try:
            CHANNELS[channel].remove(self.socket.session.session_id)
            self.channels.remove(channel)
        except ValueError:
            return False
        return True