private function getImageRetrivingClosure()
    {
        /*
         * Closure to retrieve an instnce of uploaded image with given filename
         * from request.
         *
         * @param string $filename
         * @return \Vinterskogen\UploadedImage\UploadedImage|null
         */
        return function ($filename) {
            if (! Request::hasFile($filename)) {
                return;
            }

            $uploadedFile = Request::file($filename);

            return UploadedImage::createFromBase($uploadedFile);
        };
    }