def set_handler(self, name, handler):
        if name not in self._event_stack[0]:
            self._event_stack[0][name] = RuleSet()
        ruleset = self._event_stack[0][name]
        if not hasattr(handler, 'selector'):
            handler.selector = universal_selector
        ruleset.add_rule(handler)
Parse our input and output fieldname dictionaries.
dataset/ETHPy150Open ardekantur/pyglet/contrib/layout/layout/gl/event.py/LayoutEventDispatcher.set_handler--crossover with--dataset/ETHPy150Open OpenMDAO/OpenMDAO-Framework/openmdao.lib/src/openmdao/lib/casehandlers/csvcase.py/CSVCaseIterator._parse_fieldnames