def populate(self, case_ids):
        case_ids = list(set(case_ids) - set(self.cache.keys()))
        for case in self._iter_cases(case_ids):
            self.set(_get_id_for_case(case), case)
Return true if this conduit has not been written to.
dataset/ETHPy150Open dimagi/commcare-hq/corehq/form_processor/casedb_base.py/AbstractCaseDbCache.populate--crossover with--dataset/ETHPy150Open bloomberg/phabricator-tools/py/abd/abdt_conduitmock.py/ConduitMockData.is_unchanged