def on(self, event):
        """
        Returns a wrapper for the given event.

        Usage:

            @dispatch.on("my_event")
            def handle_my_event(foo, bar, baz):
                ...

        """
        handler = self._handlers.get(event, None)
        if not handler:
            raise ValueError("Unknown event '{}'".format(event))
        return handler.register
def on ( self , event ) : handler = self . _handlers . get ( event , None ) if not handler : raise ValueError ( "Unknown event '{}'" . format ( event ) ) return handler . register
Returns a wrapper for the given event.

        Usage:

            @dispatch.on("my_event")
            def handle_my_event(foo, bar, baz):
                ...