{"ast_node_type":"variable","tokens":[{"end":18,"kind":"keyword","start":0,"text":"let"}]}
        let args =
    pub fn new_unop(tcx: TyCtxt<'tcx>, unop: mir::UnOp, ty: Ty<'tcx>, ct: Const<'tcx>) -> Self {
            tcx.mk_args_from_iter::<_, ty::GenericArg<'tcx>>([ty.into(), ct.into()].into_iter());