def __update_change(self, key, value, attr):
        "Takes key/value pair and updates change database as needed."
        if value != attr.value:
            self.__changes[key] = Parameter(value)
        elif key in self.__changes:
            del self.__changes[key]
Takes key/value pair and updates change database as needed.
recipes/Python/578173_Settings_Organizer/recipe-578173.py