code: def run():
      """Run command."""
      from mne.commands.utils import _add_verbose_flag, get_optparser
  
      parser = get_optparser(__file__)
  
      parser.add_option(
          "-d",
          "--subjects-dir",
          dest="subjects_dir",
          default=None,
          help="Subjects directory",
      )
      parser.add_option(
          "-s",
          "--subject",
          dest="subject",
          default=None,
          help="Subject name",
      )
      parser.add_option(
          "-f",
          "--fiff",
          dest="inst",
          default=None,
          help="FIFF file with digitizer data for coregistration",
      )
      parser.add_option(
          "--head-opacity",
          type=float,
          default=None,
          dest="head_opacity",
          help="The opacity of the head surface, in the range "
          "[0, 1].",
      )
      parser.add_option(
          "--high-res-head",
          action="store_true",
          default=False,
          dest="high_res_head",
          help="Use a high-resolution head surface.",
      )
      parser.add_option(
          "--low-res-head",
          action="store_true",
          default=False,
          dest="low_res_head",
          help="Use a low-resolution head surface.",
      )
      parser.add_option(
          "--trans",
          dest="trans",
          default=None,
          help='Head<->MRI transform FIF file ("-trans.fif")',
      )
      parser.add_option(
          "--interaction",
          type=str,
          default=None,
          dest="interaction",
          help='Interaction style to use, can be "trackball" or '
          '"terrain".',
      )
      _add_verbose_flag(parser)
  
      options, args = parser.parse_args()
  
      if options.low_res_head:
          if options.high_res_head:
              raise ValueError(
                  "Can't specify --high-res-head and "
                  "--low-res-head at the same time."
              )
          head_high_res = False
      elif options.high_res_head:
          head_high_res = True
      else:
          head_high_res = None
  
      # expanduser allows ~ for --subjects-dir
      subjects_dir = options.subjects_dir
      if subjects_dir is not None:
          subjects_dir = op.expanduser(subjects_dir)
      trans = options.trans
      if trans is not None:
          trans = op.expanduser(trans)
      import faulthandler
  
      faulthandler.enable()
      mne.gui.coregistration(
          inst=options.inst,
          subject=options.subject,
          subjects_dir=subjects_dir,
          head_opacity=options.head_opacity,
          head_high_res=head_high_res,
          trans=trans,
          interaction=options.interaction,
          show=True,
          block=True,
          verbose=options.verbose,
      )
  
label_desc: Use image node_id 1 for calling a global function with example usage: run() without return types