This implementation of <code>dragFinished</code> disposes the image that was created in <code>TableDragSourceEffect.dragStart</code>.
Subclasses that override this method should call <code>super.dragFinished(event)</code> to dispose the image in the default implementation.
@param event the information associated with the drag finished event
See Implementation
This implementation of <code>dragFinished</code> disposes the image that was created in <code>TableDragSourceEffect.dragStart</code>.
Subclasses that override this method should call <code>super.dragFinished(event)</code> to dispose the image in the default implementation.
@param event the information associated with the drag finished event