Question: who is the author of train to pakistan
[{'answer': 'Khushwant Singh', 'provenance': [{'wikipedia_id': '3713989', 'title': 'Train to Pakistan', 'start_paragraph_id': 1, 'start_character': 43, 'end_paragraph_id': 1, 'end_character': 58, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3713989', 'title': 'Train to Pakistan', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 354, 'bleu_score': 0.9663744727315161, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4962137817797850252}, 'section': 'Section::::Abstract.'}]}]