def set_handler(self, name, handler):
        '''Inspect handler for a selector and apply to the primary-set.
        If the handler has no selector, it is assumed to have a universal
        selector.
        '''
        if self._event_stack[0] not in name:
            self._event_stack[0][name] = RuleSet()
        ruleset = self._event_stack[0][name]
        #if not hasattr(handler, 'selector'):
            #handler.selector = universal_selector
        for selector in handler.selectors:
            ruleset.add_rule(Rule(selector, handler))
dataset/ETHPy150Open ardekantur/pyglet/contrib/wydget/wydget/event.py/GUIEventDispatcher.set_handler/swapped operands of `not in`