Method: WD_CREATE_CONTEXT
Method: WD_DESTROY_CONTEXT
Method: SET_MODELS
Method: CREATE_ITEMSET
Method: CREATE_CONTEXT_NODES
Method: EH_ONROW_SEL
Method: ON_ITEMSET_DRAG_MARK_ITEM
Method: DO_FINISH_INPUT
Method: EH_ONSORT
Method: DO_PREPARE_OUTPUT