private static boolean isSimpleExpression(@Nullable PsiExpression expression) {
      expression = PsiUtil.deparenthesizeExpression(expression);
      if (expression == null || expression instanceof PsiLiteralExpression) {
        return true;
      }
      if (expression instanceof PsiReferenceExpression) {
        PsiExpression qualifier = ((PsiReferenceExpression)expression).getQualifierExpression();
        return qualifier == null || qualifier instanceof PsiQualifiedExpression;
      }
      if (expression instanceof PsiUnaryExpression) {
        return isSimpleExpression(((PsiUnaryExpression)expression).getOperand());
      }
      return false;
    }
private static boolean isSimpleExpression(@Nullable PsiExpression expression)