src/Observing/Observer.php
public function detachObject(LifeCyclableInterface $object): ObserverInterface
    {
        $objectHash = \spl_object_hash($object);
        if (isset($this->observedList[$objectHash])) {
            $observed = $this->observedList[$objectHash];
            $object->unregisterObserver($observed);
            unset($this->observedList[$objectHash]);
        }

        return $this;
    }
public function detachObject(LifeCyclableInterface $object): ObserverInterface
    {
        $objectHash = \spl_object_hash($object);
        if (isset($this->observedList[$objectHash])) {
            $observed = $this->observedList[$objectHash];
            $object->unregisterObserver($observed);
            unset($this->observedList[$objectHash]);
        }

        return $this;
    }
{@inheritdoc}