Question: who wrote song say you won't let go
[{'answer': 'James Arthur', 'provenance': [{'wikipedia_id': '51574370', 'title': "Say You Won't Let Go", 'start_paragraph_id': 1, 'start_character': 66, 'end_paragraph_id': 1, 'end_character': 78, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '51574370', 'title': "Say You Won't Let Go", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 577, 'bleu_score': 0.9331600394719781, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15511115245296813351}, 'section': 'Section::::Abstract.'}]}]