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/impl/aggregation/sort/AggregationSortHelper.java
key );
				keyValues.add( row == null ? null:row.getAggregationValues( )[key.getAggrKeys( )[i]] );
			}
		}
		return keyValues;
	}
	/**
	 * Find next matched row in current AggregationResultRowNavigator.
	 * @param orderedArray
	 * @param values
	 * @param dirs
	 * @param sk
	 * @return
	 * @throws IOException
	 */
	private static IAggregationResultRow getNextMatchRow(
			AggregationResultRowNavigator orderedArray, Object[] values,
			boolean[] dirs, SortKey sk ) throws IOException
	{
		IAggregationResultRow currentRow = orderedArray.getCurrentRow( );
		if ( currentRow == null )
			return null;
		Object[] currentValues = new Object[values.length];
		
		for ( int y = 0; y < currentValues.length; y++ )
		{
			currentValues[y] = currentRow.getLevelMembers( )[sk.getLevelKeyOffset( )
					+ y].getKeyValues( )[0];
		}
		int i = CompareUtil.compare( values, currentValues, dirs );