def get_ref_criterion(self):
        criterions = []
        for attr in self._pkey_attrs + self._ref_attrs:
            value = attr.__get__(self, self.__class__)
            if value is not wsme.types.Unset:
                criterions.append(attr.saproperty == value)
Handles unlocking
dataset/ETHPy150Open openstack/wsme/wsmeext/sqlalchemy/types.py/Base.get_ref_criterion--crossover with--dataset/ETHPy150Open SmokinCaterpillar/pypet/pypet/utils/mpwrappers.py/LockerServer._unlock