@Override
public DragTracker getDragTracker(Request request) {
    if (REQ_SELECTION.equals(request.getType()) {
        return getParent().getDragTracker(request);
    } else return super.getDragTracker(request);
}

@Override
public DragTracker getDragTracker(Request request) {
    return new DragEditPartsTracker(this) {

        @Override
        protected List createOperationSet() {
	    List operationSet = super.createOperationSet();
	    if (operationSet.remove(getSourceEditPart())) {
	        operationSet.add(getSourceEditPart().getParent());
            }
	    return operationSet;
	}

    };
}