@memoize
    def values_sorted(self):
        return sorted(self.values(), key=null_handler)
Returns a tuple of lists of files and folders in a given directory at a
dataset/ETHPy150Open wireservice/agate/agate/columns.py/Column.values_sorted--crossover with--dataset/ETHPy150Open natestedman/Observatory/observatory/lib/pyvcs/repository.py/BaseRepository.list_directory