code: def add_parser(subparsers, parent_parser):
      GIT_HOOK_HELP = "Run GIT hook."
  
      git_hook_parser = subparsers.add_parser(
          "git-hook",
          parents=[parent_parser],
          description=GIT_HOOK_HELP,
          add_help=False,
      )
  
      git_hook_subparsers = git_hook_parser.add_subparsers(
          dest="cmd",
          help="Use `dvc daemon CMD --help` for command-specific help.",
          required=True,
      )
  
      PRE_COMMIT_HELP = "Run pre-commit GIT hook."
      pre_commit_parser = git_hook_subparsers.add_parser(
          "pre-commit",
          parents=[parent_parser],
          description=PRE_COMMIT_HELP,
          help=PRE_COMMIT_HELP,
      )
      pre_commit_parser.add_argument(
          "args",
          nargs="*",
          help="Arguments passed by GIT or pre-commit tool.",
      )
      pre_commit_parser.set_defaults(func=CmdPreCommit)
  
      POST_CHECKOUT_HELP = "Run post-checkout GIT hook."
      post_checkout_parser = git_hook_subparsers.add_parser(
          "post-checkout",
          parents=[parent_parser],
          description=POST_CHECKOUT_HELP,
          help=POST_CHECKOUT_HELP,
      )
      post_checkout_parser.add_argument(
          "args",
          nargs="*",
          help="Arguments passed by GIT or pre-commit tool.",
      )
      post_checkout_parser.set_defaults(func=CmdPostCheckout)
  
      PRE_PUSH_HELP = "Run pre-push GIT hook."
      pre_push_parser = git_hook_subparsers.add_parser(
          "pre-push",
          parents=[parent_parser],
          description=PRE_PUSH_HELP,
          help=PRE_PUSH_HELP,
      )
      pre_push_parser.add_argument(
          "args",
          nargs="*",
          help="Arguments passed by GIT or pre-commit tool.",
      )
      pre_push_parser.set_defaults(func=CmdPrePush)
  
      MERGE_DRIVER_HELP = "Run GIT merge driver."
      merge_driver_parser = git_hook_subparsers.add_parser(
          "merge-driver",
          parents=[parent_parser],
          description=MERGE_DRIVER_HELP,
          help=MERGE_DRIVER_HELP,
          formatter_class=formatter.HelpFormatter,
      )
      merge_driver_parser.add_argument(
          "--ancestor",
          required=True,
          help="Ancestor's version of the conflicting file.",
      )
      merge_driver_parser.add_argument(
          "--our",
          required=True,
          help="Current version of the conflicting file.",
      )
      merge_driver_parser.add_argument(
          "--their",
          required=True,
          help="Other branch's version of the conflicting file.",
      )
      merge_driver_parser.set_defaults(func=CmdMergeDriver)
  
imports: import os
  from dvc.cli import formatter
  from dvc.cli.command import CmdBaseNoRepo
  from dvc.exceptions import NotDvcRepoError
  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