### Question:
DMNDockSupplierImpl implements StunnerDockSupplier { @Override public Collection<UberfireDock> getDocks(String perspectiveIdentifier) { List<UberfireDock> result = new ArrayList<>(); result.add(new UberfireDock(UberfireDockPosition.EAST, PROPERTIES_DOCK_ICON, new DefaultPlaceRequest(DiagramEditorPropertiesScreen.SCREEN_ID), perspectiveIdentifier).withSize(450).withLabel(constants.DocksStunnerPropertiesTitle())); result.add(new UberfireDock(UberfireDockPosition.EAST, PREVIEW_DOCK_ICON, new DefaultPlaceRequest(PreviewDiagramScreen.SCREEN_ID), perspectiveIdentifier).withSize(450).withLabel(constants.DocksStunnerExplorerTitle())); return result; }  @Override Collection<UberfireDock> getDocks(String perspectiveIdentifier);  }### Answer:
@Test public void testDocks() { final Collection<UberfireDock> docks = supplier.getDocks(PERSPECTIVE_ID); assertEquals(2, docks.size()); final Iterator<UberfireDock> docksIterator = docks.iterator(); final UberfireDock dock1 = docksIterator.next(); final UberfireDock dock2 = docksIterator.next(); assertDock(dock1, DMNDockSupplierImpl.PROPERTIES_DOCK_ICON, DiagramEditorPropertiesScreen.SCREEN_ID, DefaultWorkbenchConstants.INSTANCE.DocksStunnerPropertiesTitle()); assertDock(dock2, DMNDockSupplierImpl.PREVIEW_DOCK_ICON, PreviewDiagramScreen.SCREEN_ID, DefaultWorkbenchConstants.INSTANCE.DocksStunnerExplorerTitle()); }