public function generateThumbnail($file)
 {
     //MAKE A THUMBNAIL COPY
     $image = File::findImage($file)->toArray()['filename'];
     if (file_exists($image)) {
         $dir = explode('students\\', File::findImage($file)->toArray()['filename'])[1];
         $folder = explode('\\', $dir);
         $file_name = explode('.', $folder[1])[0];
         $extension = explode('.', $folder[1])[1];
         mkdir(Yii::getAlias('@webroot/uploads/thumbnails/' . $folder[0]));
         Image::thumbnail($image, 64, 64)->save(Yii::getAlias('@webroot/uploads/thumbnails/' . $folder[0] . '/' . $file_name . '.' . $extension), ['quality' => 100]);
     }
 }