def get_docs_to_commit(self):
        try:
            spec = {'synced': False}
            fields = {'_id': 0}
            cur = self.db.docs.find(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        return list(cur)
def sort(cls, dataset, by=[], reverse=False):
        cols = [dataset.get_dimension(d, strict=True).name for d in by]
        return dataset.data.sort_values(by=cols, ascending=not reverse)