{"ast_node_type":"variable","tokens":[{"end":94,"kind":"keyword","start":0,"text":"let"}]}
    let unambig_to_ambig = unsafe { std::mem::transmute::<_, TyKind<'_, AmbigArg>>(unambig) };
    let unambig = TyKind::TraitObject::<'_, ()>(&[], TaggedRef::new(&lt, syntax));