Bug 182680 Use feature of new Aggregation framework of Data Engine.
DataEngine will implement new aggregation framework in 2.2.0RC0. After the implementation is finished Engine should go ahead to use new column bindings in definition of map/highlight.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/adapter/ITotalExprBindings.java
{
	/**
	 * This method returns the "new expression" in which all reference to "Total"
	 * expressions are replaced with "row" expressions. Say, "Total.count()+1" ->
	 * "row[\"TOTAL_COLUMN_1\"]+1".
	 * 
	 * @return
	 */
	public List getNewExpression( );
	
	/**
	 * This method returns an array of IColumnBinding instance, the column names of which
	 * will appears in the return of getNewExpression() method. 
	 * @return
	 */
	public IColumnBinding[] getColumnBindings();
	
}