private static String invokeImpl(PsiElement element) {
    final String text = element.getText();
    final String quote = GrStringUtil.getStartQuote(text);

    if (!("'".equals(quote) || "\"".equals(quote))) return text;
    if (!text.contains("\\n")) return text;

    String value = GrStringUtil.removeQuotes(text);

    StringBuilder buffer = new StringBuilder();
    if (element instanceof GrString) {
      processGString(element, quote, buffer);
    }
    else {
      processSimpleString(quote, value, buffer);
    }

    final String result = buffer.toString();
    if (result.endsWith("+\n\"\"")) return result.substring(0, result.length() - 4);

    return result;
  }
private static String invokeImpl(PsiElement element)