@Test
public void testGetCityList() {

    // when / then
    assertNull(model.getCityList());
    // given
    CityModel cityModel = new CityModel();
    // when
    model.addCity(cityModel);
    // then
    assertEquals(1, model.getCityList().size());
    assertTrue(model.getCityList().contains(cityModel));
    // when
    for (CityModel city : cities) {
        model.addCity(city);
    }
    // then
    assertEquals(CITIES_NUM + 1, model.getCityList().size());
    assertEquals(cityModel, model.getCityList().get(0));
}