Question: what is the current mac os operating system
[{'answer': 'macOS High Sierra', 'provenance': [{'wikipedia_id': '20640', 'title': 'MacOS', 'start_paragraph_id': 22, 'start_character': 696, 'end_paragraph_id': 22, 'end_character': 713, 'bleu_score': 1.0, 'section': 'Section::::History.:Mac OS X.:Following releases.\n'}]}, {'answer': 'macOS High Sierra , which was publicly released in September 2017'}, {'answer': '10.13. 4'}, {'provenance': [{'wikipedia_id': '20640', 'title': 'MacOS', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 780, 'bleu_score': 0.907179501172046, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5841514127147239700}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '20640', 'title': 'MacOS', 'section': 'Section::::History.:Mac OS X.:Following releases.\n', 'start_paragraph_id': 22, 'end_paragraph_id': 22, 'meta': {'evidence_span': ['Since its release, several OS X or macOS releases (namely OS X Mountain Lion, OS X El Capitan and macOS High Sierra', 'Since its release, several OS X or macOS releases (namely OS X Mountain Lion, OS X El Capitan and macOS High Sierra) follow this pattern,', "indeed it was explicitly branded to developers as being a 'no new features' release. Since its release, several OS X or macOS releases (namely OS X Mountain Lion, OS X El Capitan and macOS High Sierra) fo"]}}]}]