Question: who has the highest assist in uefa champions league history
[{'answer': 'Ryan Giggs', 'provenance': [{'wikipedia_id': '2947773', 'title': 'European Cup and UEFA Champions League records and statistics', 'start_paragraph_id': 809, 'start_character': 12, 'end_paragraph_id': 809, 'end_character': 22, 'bleu_score': 1.0, 'section': 'Section::::Players.:Goalscoring.:Other goalscoring records.\n'}]}]