@classmethod
    def filtered_on(cls, query, tag):
        # ! this assumes the ast is in the simple format without nests etc.
        for cond in query['ast']:
            if cond[0].startswith('match_tag') and cond[1] == tag:
                return cond
        return False
User should be added as a member and an owner of the group.
dataset/ETHPy150Open vimeo/graph-explorer/graph_explorer/query.py/Query.filtered_on--crossover with--dataset/ETHPy150Open ofa/connect/open_connect/groups/tests/test_views.py/GroupCreateViewTest.test_user_added_to_group