[_webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"function a() { try { s } catch(err) { var errorFlag = 'ERROR'; return errorFlag; } }; a()"]]
[_webView stringByEvaluatingJavaScriptFromString:@"function a() { try { JSON.stringify(require('BatchedBridge').flushedQueue) } catch(err) { return err.message; } }; a()"]