def METHOD_NAME(args: argparse.Namespace) -> None:
    if subparsers is None:
        print("No subcommands are available")
        return
    subcommands: list[str] = list(subparsers.choices.keys())
    if args.subcommand and args.subcommand in subcommands:
        subparsers.choices[args.subcommand].print_help()
    else:
        print("Use pydicom help [subcommand] to show help for a subcommand")
        subcommands.remove("help")
        print(f"Available subcommands: {', '.join(subcommands)}")