public function fire()
 {
     $this->info(date('Y-m-d') . ' Running RemoveOrphanedDocuments...');
     $documents = Document::whereRaw('invoice_id IS NULL AND expense_id IS NULL AND updated_at <= ?', array(new DateTime('-1 hour')))->get();
     $this->info(count($documents) . ' orphaned document(s) found');
     foreach ($documents as $document) {
         $document->delete();
     }
     $this->info('Done');
 }