code: def belanno(keyword: str, file: TextIO):
      
      directory = get_data_dir(keyword)
      obo_url = f'http://purl.obolibrary.org/obo/{keyword}.obo'
      obo_path = os.path.join(directory, f'{keyword}.obo')
      obo_cache_path = os.path.join(directory, f'{keyword}.obo.pickle')
  
      obo_getter = make_obo_getter(obo_url, obo_path, preparsed_path=obo_cache_path)
      graph = obo_getter()
      convert_obo_graph_to_belanno(
          graph,
          file=file,
      )
docs: Write as a BEL annotation.