purgeQueues example

if (!getenv('MESSENGER_AMQP_DSN')) {
            $this->markTestSkipped('The "MESSENGER_AMQP_DSN" environment variable is required.');
        }
    }

    public function testItSendsAndReceivesMessages()
    {
        $serializer = $this->createSerializer();

        $connection = Connection::fromDsn(getenv('MESSENGER_AMQP_DSN'));
        $connection->setup();
        $connection->purgeQueues();

        $sender = new AmqpSender($connection, $serializer);
        $receiver = new AmqpReceiver($connection, $serializer);

        $sender->send($first = new Envelope(new DummyMessage('First')));
        $sender->send($second = new Envelope(new DummyMessage('Second')));

        $envelopes = iterator_to_array($receiver->get());
        $this->assertCount(1, $envelopes);
        /** @var Envelope $envelope */
        $envelope = $envelopes[0];