Who was the 2020 coach of the Chicago Bulls?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q128109', 'id': 0, 'label': 'Chicago Bulls'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q174769', 'id': 1, 'label': 'United Airlines'}, {'type': 'INTERNAL', 'name_': 'Q639975', 'id': 2, 'label': 'United Center'}], 'links': [{'name_': 'P466', 'source': 2, 'target': 0, 'label': 'occupant'}, {'name_': 'P138', 'source': 2, 'target': 1, 'label': 'named after'}]}