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/api/impl/GetParameterDefinitionTask.java
{
			return Collections.EMPTY_LIST;
		}
		return this.getSelectionList( requestedParam.getName( ) );
	}
	private Collection getChoicesFromParameterGroup( ScalarParameterHandle parameter, Object[] groupKeyValues )
	{
		assert isCascadingParameter( parameter );
		CascadingParameterGroupHandle parameterGroup = getCascadingGroup( parameter );
		String parameterGroupName = parameterGroup.getName( );
			evaluateQuery( parameterGroupName );
		IResultIterator iter = (IResultIterator) dataCache.get( parameterGroupName );
		if ( iter == null )
		{
			evaluateQuery( parameterGroupName );
			if ( iter == null )
			{
				return Collections.EMPTY_LIST;
			}
		}
		String labelColumnName = LABEL_PREFIX + parameterGroupName + "_" + parameter.getName( );
		String valueColumnName = VALUE_PREFIX + parameterGroupName + "_" + parameter.getName( );
			
		int listLimit = parameter.getListlimit( );
		ArrayList choices = new ArrayList( );
		int skipLevel = groupKeyValues.length + 1;
		try
		{
			if ( skipLevel > 1 )
				iter.findGroup( groupKeyValues );