Question: who was roland in the song of roland
[{'answer': "Charlemagne 's nephew", 'provenance': [{'wikipedia_id': '226080', 'title': 'The Song of Roland', 'start_paragraph_id': 17, 'start_character': 134, 'end_paragraph_id': 17, 'end_character': 155, 'bleu_score': 1.0, 'section': 'Section::::Plot.\n'}]}, {'provenance': [{'wikipedia_id': '226080', 'title': 'The Song of Roland', 'start_paragraph_id': 17, 'start_character': 0, 'end_paragraph_id': 17, 'end_character': 457, 'bleu_score': 0.9408228243926111, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8801154420592297326}, 'section': 'Section::::Plot.\n'}]}]