{"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":".emit_err(session_diagnostics::MultipleStabilityLevels"}]}
                    .emit_err(session_diagnostics::MultipleStabilityLevels { span: cx.attr_span });
                cx.dcx()
            } else if let Some((feature, level)) = parse_unstability(cx, args) {