def install_member(self, key, implementation):
        if key in (self.STATE_ATTR, self.MANAGER_ATTR):
            raise KeyError("%r: requested attribute name conflicts with "
                           "instrumentation attribute of the same name." %
                           key)
        self.originals.setdefault(key, getattr(self.class_, key, None))
        setattr(self.class_, key, implementation)
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/orm/instrumentation.py/ClassManager.install_member/original