### Question:
KieMultipleDocumentEditor implements KieMultipleDocumentEditorPresenter<D> { @Override public IsWidget getTitleWidget(final D document) { PortablePreconditions.checkNotNull("document", document); editorView.refreshTitle(getDocumentTitle(document)); return editorView.getTitleWidget(); } KieMultipleDocumentEditor();  KieMultipleDocumentEditor(final KieEditorView editorView); @Override void registerDocument(final D document); @Override void deregisterDocument(final D document); @Override void activateDocument(final D document,
                                 final Overview overview,
                                 final AsyncPackageDataModelOracle dmo,
                                 final Imports imports,
                                 final boolean isReadOnly); @Override D getActiveDocument(); @Override IsWidget getWidget(); @Override IsWidget getTitleWidget(final D document); @Override void getMenus(final Consumer<Menus> menusConsumer); @Override void onClose(); @Override void onSourceTabSelected(); @Override void updateSource(final String source); @Override void onEditTabSelected(); @Override void onEditTabUnselected(); @Override void onOverviewSelected(); @Override boolean mayClose(final Integer originalHashCode,
                            final Integer currentHashCode); @Override Promise<Void> makeMenuBar();  }### Answer:
@Test(expected = IllegalArgumentException.class) public void testGetTitleWidgetNullDocument() { editor.getTitleWidget(null); verify(editorView, never()).refreshTitle(any(String.class)); verify(editorView, never()).getTitleWidget(); }
@Test public void testGetTitleWidget() { final TestDocument document = createTestDocument(); editor.getTitleWidget(document); verify(editorView, times(1)).refreshTitle(any(String.class)); verify(editorView, times(1)).getTitleWidget(); }