private static String prepareExpression(GrExpression expr) {
    if (PsiUtil.isThisOrSuperRef(expr)) return expr.getText();
    String text = expr.getText();

    final PsiType type = expr.getType();
    if (type != null && CommonClassNames.JAVA_LANG_STRING.equals(type.getCanonicalText())) {
      if (expr instanceof GrBinaryExpression && GroovyTokenTypes.mPLUS.equals(((GrBinaryExpression)expr).getOperationTokenType())) {
        return '(' + text + ')';
      }
      else {
        return text;
      }
    }
    else {
      return "String.valueOf(" + text + ")";
    }
  }
private static String prepareExpression(GrExpression expr)