Primavera P6 Web Services : Filtering on Specific Object Fields When Using the ExportSerivce

 I am using Primavera P6 Web Service for Exporting a Project to XML file.
 I got the following sample code from Oracle Support for filtering on Activity Filed Type :

Java :

com.primavera.ws.p6.export.BusinessObjectOptions options = new com.primavera.ws.p6.export.BusinessObjectOptions();

List actfields = new ArrayList();

actfields.add(com.primavera.ws.p6.export.ActivityFieldType.NAME);
actfields.add(com.primavera.ws.p6.export.ActivityFieldType.START_DATE);
actfields.add(com.primavera.ws.p6.export.ActivityFieldType.FINISH_DATE);
com.primavera.ws.p6.export.Activity act = new com.primavera.ws.p6.export.Activity();

act.setInclude(true);

options.setActivity(act);

But, as you can see, the List (i.e. actfields) is nowhere used in the filtering of Activities.