code: def run():
      """Run command."""
      from mne.commands.utils import _add_verbose_flag, get_optparser
  
      parser = get_optparser(__file__)
      subjects_dir = mne.get_config("SUBJECTS_DIR")
  
      parser.add_option(
          "-o",
          "--overwrite",
          dest="overwrite",
          action="store_true",
          help="Overwrite previously computed surface",
      )
      parser.add_option(
          "-s",
          "--subject",
          dest="subject",
          help="The name of the subject",
          type="str",
      )
      parser.add_option(
          "-m",
          "--mri",
          dest="mri",
          type="str",
          default="T1.mgz",
          help="The MRI file to process using mkheadsurf.",
      )
      parser.add_option(
          "-f",
          "--force",
          dest="force",
          action="store_true",
          help="Force creation of the surface even if it has "
          "some topological defects.",
      )
      parser.add_option(
          "-t",
          "--threshold",
          dest="threshold",
          type="int",
          default=20,
          help="Threshold value to use with the MRI.",
      )
      parser.add_option(
          "-d",
          "--subjects-dir",
          dest="subjects_dir",
          help="Subjects directory",
          default=subjects_dir,
      )
      parser.add_option(
          "-n",
          "--no-decimate",
          dest="no_decimate",
          help="Disable medium and sparse decimations " "(dense only)",
          action="store_true",
      )
      _add_verbose_flag(parser)
      options, args = parser.parse_args()
  
      subject = vars(options).get("subject", os.getenv("SUBJECT"))
      subjects_dir = options.subjects_dir
      if subject is None or subjects_dir is None:
          parser.print_help()
          sys.exit(1)
      make_scalp_surfaces(
          subject=subject,
          subjects_dir=subjects_dir,
          force=options.force,
          overwrite=options.overwrite,
          no_decimate=options.no_decimate,
          threshold=options.threshold,
          mri=options.mri,
          verbose=options.verbose,
      )
  
imports: import os
  import sys
  import mne
  from mne.bem import make_scalp_surfaces
label_desc: Use image node_id 1 for calling a global function with example usage: run() without return types