### Question:
DMNGridPanelControlImpl extends AbstractCanvasControl<AbstractCanvas> implements DMNGridPanelControl { @Override protected void doDestroy() { panel = null; }  @Override void bind(final DMNSession session); @Override DMNGridPanel getGridPanel();  }### Answer:
@Test public void testDoDestroy() { control.bind(session); control.doDestroy(); assertNull(control.getGridPanel()); }