Question: who played winston churchill in the darkest hour movie
[{'answer': 'Gary Oldman', 'provenance': [{'wikipedia_id': '51952238', 'title': 'Darkest Hour (film)', 'start_paragraph_id': 1, 'start_character': 120, 'end_paragraph_id': 1, 'end_character': 131, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '51952238', 'title': 'Darkest Hour (film)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 638, 'bleu_score': 0.707576073447572, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7975380880806276860}, 'section': 'Section::::Abstract.'}]}]