Web Dynpro ABAP: WD_SELECT_OPTIONS_20 events

Is there anybody out there who has experience with the events ON_LOAD_SEARCH and ON_SAVE_SEARCH of the public interface of component WD_SELECT_OPTIONS_20 ?   I found no documentation what to do, no example, nothing.   I would be grateful for any help !

(see SAP-help http://help.sap.com/saphelp_nw73ehp1/helpdata/en/2f/4c4f53087d47b19ecb1b5954be1332/content.htm?frameset=/en/4e/161363b81a20cce10000000a42189c/frameset.htm).

Thanks,

Dominik