### Question:
DetailViewModel implements ViewModel { public ReadOnlyStringProperty emailLabelTextProperty() { return email.getReadOnlyProperty(); }  void initialize(); Command getEditCommand(); Command getRemoveCommand(); Command getEmailLinkCommand(); ReadOnlyStringProperty nameLabelTextProperty(); ReadOnlyStringProperty birthdayLabelTextProperty(); ReadOnlyStringProperty roleDepartmentLabelTextProperty(); ReadOnlyStringProperty emailLabelTextProperty(); ReadOnlyStringProperty phoneLabelTextProperty(); ReadOnlyStringProperty mobileLabelTextProperty(); ReadOnlyStringProperty cityPostalcodeLabelTextProperty(); ReadOnlyStringProperty streetLabelTextProperty(); ReadOnlyStringProperty countrySubdivisionLabelTextProperty(); static final String OPEN_EDIT_CONTACT_DIALOG; }### Answer:
@Test public void testEmailLabelText() { luke.setEmailAddress("luke@rebel-alliance.com"); obi.setEmailAddress(null); selectedContact.set(null); assertThat(viewModel.emailLabelTextProperty()).hasValue(""); selectedContact.set(luke); assertThat(viewModel.emailLabelTextProperty()).hasValue("luke@rebel-alliance.com"); selectedContact.set(obi); assertThat(viewModel.emailLabelTextProperty()).hasValue(""); }