{"ast_node_type":"variable","tokens":[{"end":71,"kind":"keyword","start":0,"text":"if"}]}
            if let Some(span) = tcx.hir_span_if_local(trait_m.def_id) {
            err.span_label(impl_m_span, format!("expected `{self_descr}` in impl"));
                err.span_label(span, format!("`{self_descr}` used in trait"));