{"ast_node_type":"other","tokens":[{"end":41,"kind":"keyword","start":0,"text":"diag.span_label(span,"}]}
            diag.span_label(span, label);
            let mut diag = dcx.struct_span_err(span, format!("{label}: `{ec}`"));
            if c == '{' || c == '}' && matches!(mode, Mode::Str | Mode::RawStr) {