Who was the tenth Roman emperor?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q842606', 'id': 0, 'label': 'Roman emperor'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q111841409', 'id': 1, 'label': 'Western Roman emperor'}], 'links': [{'name_': 'P1366', 'source': 0, 'target': 1, 'label': 'replaced by'}, {'name_': 'P279', 'source': 1, 'target': 0, 'label': 'subclass of'}]}