Question: when does game of thrones season 7 start filming
[{'answer': 'August 31 , 2016', 'provenance': [{'wikipedia_id': '47398513', 'title': 'Game of Thrones (season 7)', 'start_paragraph_id': 61, 'start_character': 3, 'end_paragraph_id': 61, 'end_character': 19, 'bleu_score': 1.0, 'section': 'Section::::Production.:Casting.\n'}]}, {'provenance': [{'wikipedia_id': '47398513', 'title': 'Game of Thrones (season 7)', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 226, 'bleu_score': 0.9493253852526031, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12938160395333991165}, 'section': 'Section::::Abstract.'}]}]