pocketmine\event\HandlerList::unregister PHP Method

    public function unregister($object)
    {
        if ($object instanceof Plugin or $object instanceof Listener) {
            $changed = false;
            foreach ($this->handlerSlots as $priority => $list) {
                foreach ($list as $hash => $listener) {
                    if ($object instanceof Plugin and $listener->getPlugin() === $object or $object instanceof Listener and $listener->getListener() === $object) {
                        unset($this->handlerSlots[$priority][$hash]);
                        $changed = true;
                    }
                }
            }
            if ($changed === true) {
                $this->handlers = null;
            }
        } elseif ($object instanceof RegisteredListener) {
            if (isset($this->handlerSlots[$object->getPriority()][spl_object_hash($object)])) {
                unset($this->handlerSlots[$object->getPriority()][spl_object_hash($object)]);
                $this->handlers = null;
            }
        }
    }