Question: who did lebron james play for before the cleveland cavaliers
[{'answer': 'Miami Heat', 'provenance': [{'wikipedia_id': '240940', 'title': 'LeBron James', 'start_paragraph_id': 2, 'start_character': 534, 'end_paragraph_id': 2, 'end_character': 544, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]