### Question:
KieMultipleDocumentEditor implements KieMultipleDocumentEditorPresenter<D> { protected void openDocumentInEditor() { getAvailableDocumentPaths((allPaths) -> { for (D document : documents) { allPaths.remove(document.getLatestPath()); } if (allPaths.isEmpty()) { kieEditorWrapperView.showNoAdditionalDocuments(); } else { kieEditorWrapperView.showAdditionalDocuments(allPaths); } }); } 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 @SuppressWarnings("unchecked") public void testOpenDocumentInEditor_NoDocuments() { doAnswer((invocation) -> { final Callback<List<Path>> callback = (Callback) invocation.getArguments()[0]; callback.callback(Collections.emptyList()); return null; }).when(editor).getAvailableDocumentPaths(any(Callback.class)); editor.openDocumentInEditor(); verify(kieEditorWrapperView, times(1)).showNoAdditionalDocuments(); verify(kieEditorWrapperView, never()).showAdditionalDocuments(any(List.class)); }