Neos\Flow\Core\Booting\Scripts::initializeSignalSlot PHP Method

    public static function initializeSignalSlot(Bootstrap $bootstrap)
    {
        $bootstrap->setEarlyInstance(Dispatcher::class, new Dispatcher());
    }

 /**
  * Bootstraps the minimal infrastructure, resolves a fitting request handler and
  * then passes control over to that request handler.
  *
  * @return void
  * @api
  */
 public function run()
 {
     Scripts::initializeClassLoader($this);
     Scripts::initializeSignalSlot($this);
     Scripts::initializePackageManagement($this);
     $this->activeRequestHandler = $this->resolveRequestHandler();
     $this->activeRequestHandler->handleRequest();
 }