### Question:
DbStore implements Store, UserAddressStore { public List<String> findAllCountries() { List<String> resultList = new ArrayList<>(); try (Connection con = SOURCE.getConnection(); Statement st = con.createStatement(); ResultSet rst = st.executeQuery(PROPS.getProperty("getAllCountries"))) { while (rst.next()) { resultList.add(rst.getString("name")); } } catch (SQLException e) { LOG.error(e.getMessage(), e); } return resultList; } private  DbStore(); static DbStore getInstance(); @Override User findByLogin(String login); @Override void add(User user); @Override void update(User newUser); @Override void delete(int userId); @Override List<User> findAll(); @Override User findById(int id); List<String> findAllCountries(); List<String> findCitiesByCountry(String name);  }### Answer:
@Test public void findAllCountriesTest() { assertTrue(this.testStore.findAllCountries().containsAll(asList("Russia", "USA"))); }