def add_feature_element(self, element):
        assert self.current_feature_data is not None
        if self.current_feature_data not in 'elements':
            self.current_feature_data['elements'] = []
        self.current_feature_data['elements'].append(element)
        return element
dataset/ETHPy150Open behave/behave/behave/formatter/json.py/JSONFormatter.add_feature_element/swapped operands of `not in`