throws Throwable
  public static Value htmlspecialchars(Env env,				       Value stringV,                                       @Optional Value quoteStyleV,                                       @Optional Value charsetV)    throws Throwable  {      // XXX: quotestyle and charset    String string = stringV.toString();    StringBuilder sb = new StringBuilder();    int len = string.length();    for (int i = 0; i < len; i++) {      char ch = string.charAt(i);      switch (ch) {      case '&':        sb.append("&amp;");        break;      case '"':        sb.append("&quot;");        break;      case '\'':        sb.append("'");        break;      case '<':        sb.append("&lt;");        break;      case '>':        sb.append("&gt;");        break;      default:        sb.append(ch);        break;      }    }    return new StringValueImpl(sb.toString());  }