def update(self, iterable):
        for e in iterable:
            if self not in e:
                self._list.append(e)
                set.add(self, e)
        return self
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/util/_collections.py/OrderedSet.update/swapped operands of `not in`