src/Observing/Observer.php
public function addEventDispatcher(EventDispatcherBridgeInterface $dispatcher): ObserverInterface
    {
        $this->dispatchersList[\spl_object_hash($dispatcher)] = $dispatcher;

        return $this;
    }
public function addEventDispatcher(EventDispatcherBridgeInterface $dispatcher): ObserverInterface
    {
        $this->dispatchersList[\spl_object_hash($dispatcher)] = $dispatcher;

        return $this;
    }
{@inheritdoc}