src/Liip/Drupal/Modules/EventManager/EventSubject.php
public function detach(EventObserverInterface $observer)
    {
        $key = $this->getRegistrationKey($observer);

        if (array_key_exists($key, $this->observers)){
            unset($this->observers[$key]);
        }
    }
public function detach(EventObserverInterface $observer)
    {
        $key = $this->getRegistrationKey($observer);

        if (array_key_exists($key, $this->observers)){
            unset($this->observers[$key]);
        }
    }
public function detach ( EventObserverInterface $ observer ) { $ key = $ this -> getRegistrationKey ( $ observer ) ; if ( array_key_exists ( $ key , $ this -> observers ) ) { unset ( $ this -> observers [ $ key ] ) ; } }
Detach an EventObserver

@param \Liip\Drupal\Modules\EventManager\EventObserverInterface $observer

@link http://php.net/manual/en/splsubject.detach.php
Detach an EventObserver