/**
	 * Get the available stages for the given DataObject.
	 * 
	 * @param DataObject $dataObject
	 * 
	 * @return array
	 */
	public function getDataObjectStages(DataObject $dataObject) {
		return $dataObject->hasExtension('Versioned')?
			$dataObject->getStages():
			array('Stage');
	}