{"ast_node_type":"variable","tokens":[{"end":96,"kind":"keyword","start":0,"text":"let"}]}
            let hir::Node::GenericParam(param) = tcx.hir_node_by_def_id(def_id) else { bug!() };
        DefKind::TyParam => {
            let hir::GenericParamKind::Type { default, .. } = param.kind else { bug!() };