Question: the flash season 4 episode 1 trailer release date
[{'answer': 'July 2017', 'provenance': [{'wikipedia_id': '53527130', 'title': 'The Flash (season 4)', 'start_paragraph_id': 32, 'start_character': 3, 'end_paragraph_id': 32, 'end_character': 12, 'bleu_score': 1.0, 'section': 'Section::::Production.:Writing.\n'}]}, {'provenance': [{'wikipedia_id': '53527130', 'title': 'The Flash (season 4)', 'start_paragraph_id': 47, 'start_character': 0, 'end_paragraph_id': 47, 'end_character': 1030, 'bleu_score': 0.9755523830629911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9302920091901690688}, 'section': 'Section::::Release.:Marketing.\n'}]}]