Question: when did the ipod shuffle 4th generation come out
[{'answer': 'September 1 , 2010', 'provenance': [{'wikipedia_id': '1386785', 'title': 'IPod Shuffle', 'start_paragraph_id': 23, 'start_character': 3, 'end_paragraph_id': 23, 'end_character': 24, 'bleu_score': 1.0, 'section': 'Section::::Overview.:4th generation.\n'}]}, {'provenance': [{'wikipedia_id': '1386785', 'title': 'IPod Shuffle', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 435, 'bleu_score': 0.9738505480425671, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16672914342938457462}, 'section': 'Section::::Abstract.'}]}]