Testimonials on homepage

SS 4.4

I have from my old site 3.6 which I am updating to 4.4 dataobject testimonials on my homepage.php the code is as follows. How would this be best updated to work on 4.4 as it doesn’t. It says

[Emergency] Uncaught Error: Class ‘DataObject’ not found

public function TestimonialList($limit){
return DataObject::get(‘Testimonial’, ‘’, ‘SortOrder’, ‘’, (int)$limit);

Okay nothing like a bit of common sense sorted

	public function TestimonialList(){
		$listtestimonials = \sfimedia\testimonials\Model\Testimonial::get()->sort('SortOrder','DESC');
        $listtestimonials = $listtestimonials->limit(4);
		return $listtestimonials;