public function defaultMediaConversions()
    {
        $this->addMediaConversion('thumbnail-square')
            ->setManipulations(['w' => 256, 'h' => 256, 'fit' => 'crop'])
            ->performOnCollections('images');

        $this->addMediaConversion('thumbnail-small')
            ->setManipulations(['w' => 250, 'h' => 250, 'fit' => 'max'])
            ->performOnCollections('images');

        $this->addMediaConversion('thumbnail-medium')
            ->setManipulations(['w' => 420, 'h' => 420, 'fit' => 'max'])
            ->performOnCollections('images');

        $this->addMediaConversion('thumbnail-large')
            ->setManipulations(['w' => 600, 'h' => 600, 'fit' => 'max'])
            ->performOnCollections('images');

        $this->addMediaConversion('originalHD')
            ->setManipulations(['w' => 1920, 'h' => 1080, 'fit' => 'max'])
            ->performOnCollections('images');
    }