def isValid(self, value):
        return value is None if self._onlyNullAllowed else value is not None
Copies the locations.yaml and locations.json files found locally (which
dataset/ETHPy150Open rwl/muntjac/muntjac/data/validators/null_validator.py/NullValidator.isValid--crossover with--dataset/ETHPy150Open AppScale/appscale-tools/lib/remote_helper.py/RemoteHelper.copy_local_metadata