def chain(self, visitor):
        tail = list(self._visitor_iterator)[-1]
        tail._next = visitor
        return self
'chain' an additional ClauseVisitor onto this ClauseVisitor.
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/sql/visitors.py/ClauseVisitor.chain