docs: def get_argument_parser():
      """Function to obtain the argument parser.
  
      Returns
      -------
      A fully configured `argparse.ArgumentParser` object.
  
      Notes
      -----
      This function is used by the `sphinx-argparse` extension for sphinx.
  
      """
      file_mv = cli.file_mv
  
      desc = 'Extracts gene-level expression data from StringTie output.'
      parser = cli.get_argument_parser(desc)
  
      parser.add_argument(
          '-s', '--stringtie-file', type=str, required=True, metavar=file_mv,
          help="""Path of the StringTie output file ."""
      )
  
      parser.add_argument(
          '-g', '--gene-file', type=str, required=True, metavar=file_mv,
          help="""File containing a list of protein-coding genes."""
      )
  
      parser.add_argument(
          '--no-novel-transcripts', action='store_true',
          help="""Ignore novel transcripts."""
      )
  
      # parser.add_argument(
      #     '--ambiguous-transcripts', default = 'ignore',
      #      help='Strategy for counting expression of ambiguous novel '
      #            'transcripts.'
      # )
      # possible strategies for ambiguous transcripts: 'ignore','highest','all'
  
      parser.add_argument(
          '-o', '--output-file', type=str, required=True, metavar=file_mv,
          help="""Path of output file."""
      )
  
      cli.add_reporting_args(parser)
  
      return parser