Bug 213663 [2.2.2][2.3.0]Exception occurs when preview a datetime type data with highlight rule
data/org.eclipse.birt.report.data.adapter/src/org/eclipse/birt/report/data/adapter/api/DataAdapterUtil.java
{
	private static Map aggrAdapterMap = new HashMap( );
	private static Map filterOptMap = new HashMap( );
	static
	{
		registerAggregationFunction( );
		registerFilterOperator( );
	}
	/**
	 * register model aggregation function names with build-in function names	
	 */
	private static void registerAggregationFunction( )
	{
		aggrAdapterMap.put( DesignChoiceConstants.AGGREGATION_FUNCTION_SUM,
				IBuildInAggregation.TOTAL_SUM_FUNC );