def get_dbref(self):
        assert '_id' in self, "You must specify an '_id' for using this method"
        return DBRef(database=self.db.name, collection=self.collection.name, id=self['_id'])
return a pymongo DBRef instance related to the document
dataset/ETHPy150Open namlook/mongokit/mongokit/document.py/Document.get_dbref