{"ast_node_type":"variable","tokens":[{"end":52,"kind":"keyword","start":0,"text":"let"}]}
                    let pinned_ty = args.type_at(0);
                ty::Adt(def, args) if cx.tcx.is_lang_item(def.did(), LangItem::Pin) => {
                    is_ty_must_use(cx, pinned_ty, expr, span)