AMQPConnection::isConnected PHP Méthode

    public function isConnected()
    {
    }

 /**
  * @param callable $callback
  * @throws NotSubscribedListenerException
  * @throws \Exception
  * @return void
  */
 public function subscribe(callable $callback)
 {
     $this->callback = $callback;
     //Check whether connection open or not
     if (!$this->connection->isConnected()) {
         $this->connection->connect();
     }
     /** Declare exchange. In case it is already exists it could change it's options */
     $this->declareExchange();
     //Binding queue to correct exchange
     if (!$this->getQueue()->bind($this->exchangeConfig['name'])) {
         throw new NotSubscribedListenerException("Can not bind " . $this->getQueue()->getName() . " to an exchange " . $this->exchangeConfig);
     }
     $callback = function (\AMQPEnvelope $message) {
         switch ($message->getType()) {
             //Stop consumer by special event
             case 'eventBus.consumer-stop':
                 $this->getQueue()->ack($message->getDeliveryTag());
                 call_user_func($this->callback, 'eventBus.consumer-stop');
                 $this->stopConsumer();
                 break;
             default:
                 //If publisher is same BC as subscriber, don't proceed
                 if ($message->getAppId() !== $this->getQueue()->getName()) {
                     call_user_func($this->callback, $this->unpackMessage($message));
                 }
         }
         //Answering to RabbitMQ, that event processed
         $this->getQueue()->ack($message->getDeliveryTag());
     };
     $callback->bindTo($this);
     //Listen events
     $this->getQueue()->consume($callback);
 }