Question: who did the american federation of labor represent
[{'answer': 'an association of trade unions', 'provenance': [{'wikipedia_id': '350020', 'title': 'American Federation of Labor', 'start_paragraph_id': 5, 'start_character': 56, 'end_paragraph_id': 5, 'end_character': 86, 'bleu_score': 1.0, 'section': 'Section::::Organizational history.:Origins.\n'}]}, {'provenance': [{'wikipedia_id': '350020', 'title': 'American Federation of Labor', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 582, 'bleu_score': 0.9635165832749841, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14546856417396935174}, 'section': 'Section::::Organizational history.:Origins.\n'}]}]