Question: what is the purpose of a governor on an engine
[{'answer': 'measure and regulate the speed', 'provenance': [{'wikipedia_id': '430361', 'title': 'Governor (device)', 'start_paragraph_id': 1, 'start_character': 64, 'end_paragraph_id': 1, 'end_character': 94, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '430361', 'title': 'Governor (device)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 126, 'bleu_score': 0.9181891462193901, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7748618701989854985}, 'section': 'Section::::Abstract.'}]}]