### Question:
AboutViewModel implements ViewModel { public ReadOnlyStringProperty librariesLabelTextProperty() { return librariesLabelText.getReadOnlyProperty(); } AboutViewModel(); @PostConstruct void initLibraryMap(); void onLinkClicked(String linkText); ReadOnlyStringProperty librariesLabelTextProperty();  }### Answer:
@Test public void testLibrariesLabel() { ReadOnlyStringProperty libraries = viewModel.librariesLabelTextProperty(); assertThat(libraries).hasValue(""); viewModel.libraryLinkMap.put(MY_COOL_LIB_NAME, MY_COOL_LIB_URL); assertThat(libraries).hasValue("- [my cool library]\n"); viewModel.libraryLinkMap.put(OTHER_FX_NAME, OTHER_FX_URL); assertThat(libraries).hasValue("- [my cool library]\n- [otherFX]\n"); }