code: public static String unescape(Object content)
      {
          if (content == null) {
              return null;
          }
          String str = String.valueOf(content);
  
          str = APOS_PATTERN.matcher(str).replaceAll("'");
          str = QUOT_PATTERN.matcher(str).replaceAll("\"");
          str = LT_PATTERN.matcher(str).replaceAll("<");
          str = GT_PATTERN.matcher(str).replaceAll(">");
          str = AMP_PATTERN.matcher(str).replaceAll("&");
          str = LCURL_PATTERN.matcher(str).replaceAll("{");
  
          return str;
      }
docs: Unescape encoded special XML characters. Only &gt;, &lt; &amp;, ", ' and { are unescaped, since they are the only
  ones that affect the resulting markup.
  
  @param content the text to decode, may be {@code null}
  @return unescaped content, {@code null} if {@code null} input