protected function createThumbnail()
    {
		$this->thumbnail = $this->thumbnailName();

    	if (! $this->validFile($this->thumbnailPath())) {
    		$img = $this->intervention
				->make($this->imagePath())
				->resize($this->width(), $this->height(), function ($constraint) {
            		$constraint->aspectRatio();
            		$constraint->upsize();
        		});

        	$img->save($this->thumbnailPath());
    	}
    }