public function rotate($background = 'white', $deg = 0, $exif = false)
    {
        $options = [
            'b' => $background,
            'd' => $deg,
            'e' => $exif ? 'true' : 'false'
        ];

        // call TransformationMixin function
        $this->setTransformUrl('rotate', $options);

        return $this;
    }