if i use same throttle class in different api, any one api will affect the others' throttling, because they use same cache key in class.
i don't want to write many same throttle class that only changing cache key inside.
so change the above code to support this situation.
https://github.com/waro163/flask-restframework/blob/987565683717c0c7cb9edfcdc318fd847377fae6/flask_restframework/throttling.py#L91-L127
if i use same throttle class in different api, any one api will affect the others' throttling, because they use same cache key in class. i don't want to write many same throttle class that only changing cache key inside. so change the above code to support this situation.