syntax_data: {"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"Some(trait_ref)"}]}
source_snippet:                 Some(trait_ref) => trait_ref.skip_binder().args.types().collect(),
context_before:             let tys = match tcx.impl_trait_ref(def_id) {
context_after:                 None => vec![tcx.type_of(def_id).instantiate_identity()],