protected void setupUrlConnection(HttpURLConnection urlConnection) throws Exception {
   JSONObject requestData = getRequestData();
   if (requestData == null) {
     super.setupUrlConnection(urlConnection);
     return;
   }
   byte[] content = requestData.toString().getBytes(HttpRequest.CHARSET_UTF8);
   urlConnection.setDoOutput(true);
   urlConnection.setInstanceFollowRedirects(false);
   super.setupUrlConnection(urlConnection);
   urlConnection.setRequestProperty(
       HttpRequest.HEADER_CONTENT_TYPE, "application/json;charset=utf-8");
   urlConnection.setRequestProperty(
       HttpRequest.HEADER_CONTENT_LENGTH, BuildConfig.FLAVOR + content.length);
   OutputStream outputStream = urlConnection.getOutputStream();
   try {
     outputStream.write(content);
   } finally {
     outputStream.close();
   }
 }
 public Double execute() throws Exception {
   return JsonUtils.getDouble(WebApiCommand.getData(executeRequest()), "credit");
 }