/**
  * @param string $key
  *
  * @return ExportJob|null
  */
 public function findByKey(string $key) : ExportJob
 {
     $result = $this->user->exportJobs()->where('key', $key)->first(['export_jobs.*']);
     if (is_null($result)) {
         return new ExportJob();
     }
     return $result;
 }