Question: who attacked first in the battle of cold harbor
[{'answer': 'the Union', 'provenance': [{'wikipedia_id': '48965', 'title': 'Battle of Cold Harbor', 'start_paragraph_id': 2, 'start_character': 258, 'end_paragraph_id': 2, 'end_character': 267, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '48965', 'title': 'Battle of Cold Harbor', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 555, 'bleu_score': 0.978375183951072, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12399529936540310231}, 'section': 'Section::::Abstract.'}]}]