code: def add_parser(subparsers, parent_parser):
      FREEZE_HELP = "Freeze stages or .dvc files."
      freeze_parser = subparsers.add_parser(
          "freeze",
          parents=[parent_parser],
          description=append_doc_link(FREEZE_HELP, "freeze"),
          help=FREEZE_HELP,
          formatter_class=formatter.RawDescriptionHelpFormatter,
      )
      freeze_parser.add_argument(
          "targets", nargs="+", help="Stages or .dvc files to freeze"
      ).complete = completion.DVC_FILE
      freeze_parser.set_defaults(func=CmdFreeze)
  
      UNFREEZE_HELP = "Unfreeze stages or .dvc files."
      unfreeze_parser = subparsers.add_parser(
          "unfreeze",
          parents=[parent_parser],
          description=append_doc_link(UNFREEZE_HELP, "unfreeze"),
          help=UNFREEZE_HELP,
          formatter_class=formatter.RawDescriptionHelpFormatter,
      )
      unfreeze_parser.add_argument(
          "targets", nargs="+", help="Stages or .dvc files to unfreeze"
      ).complete = completion.DVC_FILE
      unfreeze_parser.set_defaults(func=CmdUnfreeze)
  
file_path: dvc/dvc/commands/freeze.py
imports: from dvc.cli import completion, formatter
  from dvc.cli.command import CmdBase
  from dvc.cli.utils import append_doc_link
  from dvc.exceptions import DvcException
  from dvc.log import logger
label_desc: Use image node_id 1 for calling a global function with example usage: add_parser(subparsers, parent_parser) without return types