public function getAllByModel($itemModel)
    {
        if (!empty($itemModel)) {
            $uri = ($itemModel instanceof core_kernel_classes_Resource) ? $itemModel->getUri() : $itemModel;
            return $this->itemClass->searchInstances(array(
                $this->itemModelProperty->getUri() => $uri
            ), array(
                'recursive' => true
            ));
        }
        return array();
    }