Question: who is the general brad pitt plays in war machine
[{'answer': 'Glen McMahon', 'provenance': [{'wikipedia_id': '47496109', 'title': 'War Machine (film)', 'start_paragraph_id': 4, 'start_character': 41, 'end_paragraph_id': 4, 'end_character': 53, 'bleu_score': 1.0, 'section': 'Section::::Plot.\n'}]}, {'provenance': [{'wikipedia_id': '47496109', 'title': 'War Machine (film)', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 774, 'bleu_score': 0.8183869873401911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18028712197386478012}, 'section': 'Section::::Plot.\n'}]}]