Who was the leader of the country that attacked Pearl Harbor?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q52418', 'id': 0, 'label': 'Attack on Pearl Harbor'}, {'type': 'INTERNAL', 'name_': 'Q258092', 'id': 1, 'label': 'Tora Tora Tora'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q295839', 'id': 2, 'label': 'Chūichi Nagumo'}], 'links': [{'name_': 'P921', 'source': 1, 'target': 0, 'label': 'main subject'}, {'name_': 'P674', 'source': 1, 'target': 2, 'label': 'characters'}]}