Bug 182895 Support sort on Level attribute.
Currently in OLAP engine we only support sort on level key value. We should go ahead to support sort on level attribute value.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/olap/data/api/CubeQueryExecutorHelper.java
* @return
	 */
	public IDiskArray getLevelMembers( DimLevel level )
	{
		return null;
	}
	
	/**
	 * get the attribute reference name.
	 * @param dimName
	 * @param levelName
	 * @param attrName
	 * @return
	 */
	public static String getAttrReference( String dimName, String levelName, String attrName )
	{
		return dimName + '/' + levelName + '/' + attrName;
	}
	
	
	/**
	 * 
	 * @param cube
	 * @throws BirtException 
	 * @throws IOException 
	 */
	public static ICube loadCube( String cubeName,
			IDocumentManager documentManager, StopSign stopSign ) throws IOException, DataException
	{
		Cube cube = new Cube( cubeName, documentManager );