/**
  * Set unique name for file
  *
  * @param File $file
  * @return File
  */
 public function file(File $file)
 {
     if (FileSystem::exists($file->fullPath())) {
         $original_name = $file->name();
         $file->setName($original_name . '-1');
         for ($i = 2; FileSystem::exists($file->fullPath()); $i++) {
             $file->setName($original_name . '-' . $i);
         }
     }
     return $file;
 }