def getall(self):
        try:
            spec = {'data': {'$exists': 1}}
            fields = {'_id': 0}
            sort = [('tid', 1)]
            cur = self.db.docs.find(spec, fields, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        return [Document(**row) for row in cur]
def test_abstract_class(self):
        class X(Structure):
            _abstract_ = "something"
        # try 'X()'
        cls, msg = self.get_except(eval, "X()", locals())
        self.assertEqual((cls, msg), (TypeError, "abstract class"))