Question: who plays blue fairy in once upon a time
[{'answer': 'Keegan Connor Tracy', 'provenance': [{'wikipedia_id': '4133502', 'title': 'Keegan Connor Tracy', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 19, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]