@arg('command', metavar='<subcommand>', nargs='?', help='Display help for <subcommand>')
    def do_help(self, args):
        if args.command:
            if args.command in self.subcommands:
                self.subcommands[args.command].print_help()
            else:
                raise CommandError("'%s' is not a valid subcommand." % args.command)
        else:
            self.parser.print_help()
Display help about this program or one of its subcommands.
dataset/ETHPy150Open jacobian-archive/openstack.compute/openstack/compute/shell.py/ComputeShell.do_help