Question: when does wally west becomes a speedster in the flash
[{'answer': '1959', 'provenance': [{'wikipedia_id': '1257796', 'title': 'Wally West', 'start_paragraph_id': 1, 'start_character': 285, 'end_paragraph_id': 1, 'end_character': 289, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]