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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def sort(self, key_or_list, direction=None):
 """Sorts this cursor's results. Pass a field name and a direction, either :data:`~pymongo.ASCENDING` or :data:`~pymongo.DESCENDING`:: for doc in collection.find().sort('field', pymongo.ASCENDING):
 print(doc) To sort by multiple fields, pass a list of (key, direction) pairs:: for doc in collection.find().sort([ ('field1', pymongo.ASCENDING), ('field2', pymongo.DESCENDING)]):
 print(doc) Beginning with MongoDB version 2.6, text search results can be sorted by relevance:: cursor = db.test.find( {'$text': {'$search': 'some words'}}, {'score': {'$meta': 'textScore'}}) # Sort by 'score' field. cursor.sort([('score', {'$meta': 'textScore'})]) for doc in cursor: print(doc) Raises :class:`~pymongo.errors.InvalidOperation` if this cursor has already been used. Only the last :meth:`sort` applied to this cursor has any effect. :Parameters: - `key_or_list`: a single key or a list of (key, direction) pairs specifying the keys to sort on - `direction` (optional):
 only used if `key_or_list` is a single key, if not given :data:`~pymongo.ASCENDING` is assumed """

        self.__check_okay_to_chain()
        keys = helpers._index_list(key_or_list, direction)
        self.__ordering = helpers._index_document(keys)
        return self