def is_valid_filter(self, filter):
        return isinstance(filter, BasePyMongoFilter)
Return the number of pageviews by question in a given date range.
dataset/ETHPy150Open flask-admin/flask-admin/flask_admin/contrib/pymongo/view.py/ModelView.is_valid_filter--crossover with--dataset/ETHPy150Open mozilla/kitsune/kitsune/sumo/googleanalytics.py/pageviews_by_question