/**
  * Delete
  *
  * @param integer $no
  * @return bool
  */
 public function delete($no)
 {
     $handle = $this->getHandle($no);
     try {
         $this->client->Subscription_Delete(['subscriptionHandle' => $handle]);
     } catch (Exception $e) {
         return false;
     }
     return true;
 }