code: private static String decodeFormFields (final String content, final String charset) {
          if (content == null) {
              return null;
          }
          return urldecode(content, charset != null ? Charset.forName(charset) : Consts.UTF_8, true);
      }
docs: Decode/unescape www-url-form-encoded content.
  
  @param content the content to decode, will decode '+' as space
  @param charset the charset to use
  @return