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.tests/test/org/eclipse/birt/data/engine/olap/api/CubeFeaturesTest.java
dataCursor.close( );
	}
	
	private void createCube( DataEngine engine ) throws BirtException, IOException
	{
		IDocumentManager documentManager = DocumentManagerFactory.createFileDocumentManager( documentPath + engine.hashCode( ), cubeName);
		DocManagerMap.getDocManagerMap( ).set( String.valueOf( engine.hashCode( ) ), documentPath + engine.hashCode( ) + cubeName, documentManager );
		engine.addShutdownListener( new DocManagerReleaser( engine ) );
		Dimension[] dimensions = new Dimension[2];
		
		String[] levelNames = new String[3];
		levelNames[0] = "level11";
		levelNames[1] = "level12";
		levelNames[2] = "level13";
		DimensionForTest iterator = new DimensionForTest( levelNames );
		iterator.setLevelMember( 0, TestFactTable.DIM0_L1Col );
		iterator.setLevelMember( 1, TestFactTable.DIM0_L2Col );
		iterator.setLevelMember( 2, TestFactTable.DIM0_L3Col );
		ILevelDefn[] levelDefs = new ILevelDefn[3];
		levelDefs[0] = new LevelDefinition( "level11", new String[]{
			"level11"
		}, null );
		levelDefs[1] = new LevelDefinition( "level12", new String[]{
			"level12"
		}, null );
		levelDefs[2] = new LevelDefinition( "level13", new String[]{
			"level13"
		}, null );
		dimensions[0] = (Dimension) DimensionFactory.createDimension( "dimension1",
				documentManager,