public function remove(AbstractEntity $instance)
    {
        $class = get_class($instance);
        $entityPool = $this->pool[$class] ?? [];
        $id = '' . $instance->id;
        if (isset($entityPool[$id])) {
            unset($entityPool[$id]);
            $this->pool[$class] = $entityPool;
        }
        unset($instance);

        return true;
    }