How to use the ghstack.unlink.main function in ghstack

def gh_unlink(self) -> None:
        ghstack.unlink.main(
            sh=self.sh
        )

if args.cmd == 'rage':
            ghstack.rage.main(latest=args.latest)
        elif args.cmd == 'submit':
            ghstack.submit.main(
                msg=args.message,
                username=conf.github_username,
                sh=sh,
                github=github,
                update_fields=args.update_fields,
                short=args.short,
                force=args.force,
                no_skip=args.no_skip,
            )
        elif args.cmd == 'unlink':
            ghstack.unlink.main(
                commits=args.COMMITS,
                sh=sh,
            )
        elif args.cmd == 'land':
            ghstack.land.main(
                pull_request=args.pull_request,
                github=github,
                sh=sh,
            )
        elif args.cmd == 'action':
            ghstack.action.main(
                pull_request=args.pull_request,
                github=github,
                sh=sh,
                close=args.close,
            )