Question: what episode does negan appear in the walking dead
[{'answer': 'sixth season finale', 'provenance': [{'wikipedia_id': '41298016', 'title': 'Negan', 'start_paragraph_id': 1, 'start_character': 594, 'end_paragraph_id': 1, 'end_character': 613, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '41298016', 'title': 'Negan', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 613, 'bleu_score': 0.925800253895223, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6095241369787469449}, 'section': 'Section::::Abstract.'}]}]