def _init_trait_listeners(self):
        """ Force the DelegatesTo listener to hook up first to exercise the
        worst case.
        """
        for name in ['y', '_on_dummy1_x']:
            data = self.__class__.__listener_traits__[name]
            getattr(self, data[0] % '_init_trait_%s_listener')(name, *data)
dataset/ETHPy150Open enthought/traits/traits/tests/test_regression.py/DelegateMess._init_trait_listeners/swapped operands of `%`