def mappings(self, year=None):
        mappings = []
        for yr, elecs in self.elections(year).items():
            mappings.extend(self._build_metadata(yr, elecs))
        return mappings
Invoke list_pop() with key is none
dataset/ETHPy150Open openelections/openelections-core/openelex/us/id/datasource.py/Datasource.mappings--crossover with--dataset/ETHPy150Open aerospike/aerospike-client-python/test/old_tests/_test_list_pop.py/TestListPop.test_list_pop_key_is_none