def add_class(self, name, cls):
        if name in self.contents:
            existing = self.contents[name]
            existing.add_item(cls)
        else:
            existing = self.contents[name] = \
                _MultipleClassMarker([cls],
                                     on_remove=lambda: self._remove_item(name))
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/ext/declarative/clsregistry.py/_ModuleMarker.add_class/original