docs: private static String getResponseStringData(InputStream is, String charset) throws IOException {
      ByteArrayOutputStream respDataStream = new ByteArrayOutputStream();
      String result;
      try {
        byte[] b = new byte[8192];
        int len;
        while (true) {
          len = is.read(b);
          if (len <= 0) {
            is.close();
            break;
          }
          respDataStream.write(b, 0, len);
        }
        result = respDataStream.toString(charset);
      } finally {
        respDataStream.close();
      }
      return result;
    }