/**
  * @param Channel $channel
  *
  * @depends testSubscribe
  */
 public function testUnSubscriber(Channel $channel)
 {
     $subscribers = $channel->getSubscribers();
     $this->assertCount(2, $subscribers);
     $subscriber = array_pop($subscribers);
     $this->assertTrue($channel->unSubscribe($subscriber));
     $subscribers = $channel->getSubscribers();
     $this->assertCount(1, $subscribers);
     $subscriber = array_pop($subscribers);
     $this->assertTrue($channel->unSubscribe($subscriber));
     $subscribers = $channel->getSubscribers();
     $this->assertCount(0, $subscribers);
     $this->assertCount(0, $channel->getSubscribers());
     $this->assertTrue($channel->delete());
 }