#NEWLINE# def register_handler( self , event , handler ) : #NEWLINE# #INDENT# '\n        Registers a handler to be triggered by an event\n\n        :param event: The event to handle\n        :param handler: The handler callable.\n        :return: A handle that can be used to unregister the handler.\n        ' #NEWLINE# return self . __handler . register_handler ( event , event )