With which football team did Herschel Walker begin his NFL career?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q912985', 'id': 0, 'label': 'running back'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q1215884', 'id': 1, 'label': 'National Football League'}, {'type': 'INTERNAL', 'name_': 'Q3701745', 'id': 2, 'label': 'Daniel Thomas'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q609950', 'id': 3, 'label': 'Herschel Walker'}], 'links': [{'name_': 'P413', 'source': 2, 'target': 0, 'label': 'position played on team / speciality'}, {'name_': 'P118', 'source': 2, 'target': 1, 'label': 'league'}, {'name_': 'P413', 'source': 3, 'target': 0, 'label': 'position played on team / speciality'}]}