@Test
public void testAddMouseDownHandlerAttachesToRootPanel() {

    //Ensure nobody thinks its a good idea to attach to the GridPanel at some time in the future!
    //See https://issues.jboss.org/browse/GUVNOR-3491
    final MouseDownHandler handler = mock(MouseDownHandler.class);
    view.addMouseDownHandler(handler);
    verify(mockGridPanel,
           never()).addMouseDownHandler(eq(handler));
    verify(rootPanel).addDomHandler(eq(handler),
                                    eq(MouseDownEvent.getType()));
}