Question: when did pokhran ii nuclear tests take place
[{'answer': 'May 1998', 'provenance': [{'wikipedia_id': '2188274', 'title': 'Pokhran-II', 'start_paragraph_id': 1, 'start_character': 134, 'end_paragraph_id': 1, 'end_character': 142, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2188274', 'title': 'Pokhran-II', 'start_paragraph_id': 1, 'start_character': 28, 'end_paragraph_id': 1, 'end_character': 280, 'bleu_score': 0.7677307738500391, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3402963217494891742}, 'section': 'Section::::Abstract.'}]}]