/**
  * {@inheritdoc}
  *
  * @param WorkerInterface $worker
  * @return bool
  */
 public function attach(WorkerInterface $worker)
 {
     if (count($this->workers) === $this->configuration->getProcesses()) {
         return false;
     }
     $this->workers->attach($worker);
     if (!$worker->isStarted()) {
         $worker->start();
     }
     $this->broker->addMessage(new TestMessage($worker->getOutputStream()));
     return true;
 }