What is the song that has been number one the longest?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q7366', 'id': 0, 'label': 'song'}, {'type': 'INTERNAL', 'name_': 'Q134556', 'id': 1, 'label': 'single'}, {'type': 'INTERNAL', 'name_': 'Q175728', 'id': 2, 'label': 'list of number-one singles in Australia during the 1990s'}, {'type': 'INTERNAL', 'name_': 'Q373899', 'id': 3, 'label': 'record chart'}, {'type': 'INTERNAL', 'name_': 'Q2291', 'id': 4, 'label': 'Totò'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q20878491', 'id': 5, 'label': 'number-one hit'}, {'type': 'INTERNAL', 'name_': 'Q20796013', 'id': 6, 'label': 'number one hit in Australia'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q62587323', 'id': 7, 'label': 'Old Town Road'}, {'type': 'INTERNAL', 'name_': 'Q64762097', 'id': 8, 'label': 'Panini'}], 'links': [{'name_': 'P1963', 'source': 1, 'target': 4, 'label': 'properties for this type'}, {'name_': 'P360', 'source': 2, 'target': 1, 'label': 'is a list of'}, {'name_': 'P1687', 'source': 3, 'target': 4, 'label': 'Wikidata property'}, {'name_': 'P527', 'source': 3, 'target': 5, 'label': 'has part(s)'}, {'name_': 'P2354', 'source': 6, 'target': 2, 'label': 'has list'}, {'name_': 'P279', 'source': 6, 'target': 5, 'label': 'subclass of'}, {'name_': 'P31', 'source': 7, 'target': 1, 'label': 'instance of'}, {'name_': 'P156', 'source': 7, 'target': 8, 'label': 'followed by'}, {'name_': 'P7937', 'source': 8, 'target': 0, 'label': 'form of creative work'}, {'name_': 'P155', 'source': 8, 'target': 7, 'label': 'follows'}]}