syntax_data: {"ast_node_type":"function","tokens":[{"end":97,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub fn new_opaque(tcx: TyCtxt<'tcx>, def_id: DefId, args: GenericArgsRef<'tcx>) -> Ty<'tcx> {
context_before:     #[instrument(level = "debug", skip(tcx))]
context_after:         Ty::new_alias(tcx, ty::Opaque, AliasTy::new_from_args(tcx, def_id, args))