def test_validate_handler_function_args_controller_valid(self):
        def x():
            pass

        InterfaceEventDispatcher._validate_handler_function_args(x, True)
    def test_validate_handler_function_args_controller_too_many(self):
        def x(a):
            pass

        with self.assertRaises(InvalidEventHandler):
            InterfaceEventDispatcher._validate_handler_function_args(x, True)
    def test_validate_handler_function_args_not_controller_too_few(self):
        def x():
            pass

        with self.assertRaises(InvalidEventHandler):
            InterfaceEventDispatcher._validate_handler_function_args(x, False)