Process::start PHP Method

    public function start($state)
    {
        foreach ($state['neighbors'] as $idj) {
            $this->send($idj, new Message('position', array('id' => $this->self(), 'neighbors' => $state['neighbors'])));
        }
        $state['part'] = true;
        return $state;
    }

 /**
  * Asynchronously start mediainfo operation.
  * Make call to MediaInfoCommandRunner::wait() afterwards to receive output.
  */
 public function start()
 {
     $this->processBuilder->add($this->filePath);
     $this->processAsync = $this->processBuilder->getProcess();
     // just takes advantage of symfony's underlying Process framework
     // process runs in background
     $this->processAsync->start();
 }