protected function _includeResource(ModelEntityInterface $entity)
    {
        $cache  = $entity->getIdentifier()->name.'-'.$entity->getHandle();

        if (!isset($this->_included_resources[$cache])) {
            $this->_included_resources[$cache] = $this->_createResource($entity, array('relationships' => false));
        }

        $resource = $this->_included_resources[$cache];

        return array(
            'data' => array(
                'type' => $resource['type'],
                'id'   => $resource['id']
            )
        );
    }