{"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"err.span_label(impl_m_span,"}]}
            err.span_label(impl_m_span, format!("expected `{self_descr}` in impl"));
            );
            if let Some(span) = tcx.hir_span_if_local(trait_m.def_id) {