def subscribe(self):
        """Register this object as a (multi-channel) listener on the bus."""
        for channel in self.bus.listeners:
            # Subscribe self.start, self.exit, etc. if present.
            method = getattr(self, channel, None)
            if method is not None:
                self.bus.subscribe(channel, method)
Register this object as a (multi-channel) listener on the bus.
cherrypy/process/plugins.py