def hint(self, index):
        self.__check_okay_to_chain()
        if index is None:
            self.__hint = None
            return self

        self.__hint = helpers._index_document(index)
        return self
Adds a 'hint', telling Mongo the proper index to use for the query.
dataset/ETHPy150Open blynch/CloudMemeBackend/pymongo/cursor.py/Cursor.hint