### Question:
NavigationService { public FXMLLoader createLoader(final String fxmlFile) throws IOException { return fxmlLoader.create(fxmlFile); } @Inject  NavigationService(IFxmlLoaderProvider loader); void setNavigationController(INavigatable controller); INavigatable getNavigationController(); FXMLLoader createLoader(final String fxmlFile); synchronized void navigate(final String fxmlFile); synchronized void navigateBack(); synchronized boolean canNavigateBack(); synchronized void clearPages();  }### Answer:
@Test public void testCreateLoader() throws IOException { final String page = "/testpage1.fxml"; navigationService.createLoader(page); Mockito.verify(fxmlLoaderProvider, Mockito.times(1)).create(page); }