### Question:
PhoneNumber { public static boolean isCountryValid(PhoneNumber phoneNumber) { return phoneNumber != null && !EMPTY_PHONE_NUMBER.equals(phoneNumber) && !TextUtils .isEmpty(phoneNumber.getCountryCode()) && !TextUtils.isEmpty(phoneNumber .getCountryIso()); } PhoneNumber(String phoneNumber, String countryIso, String countryCode); static PhoneNumber emptyPhone(); String getCountryCode(); String getPhoneNumber(); String getCountryIso(); static boolean isValid(PhoneNumber phoneNumber); static boolean isCountryValid(PhoneNumber phoneNumber);  }### Answer:
@Test public void testIsCountryValid_nullPhone() throws Exception { assertFalse(PhoneNumber.isCountryValid(null)); }
@Test public void testIsCountryValid_emptyMembers() throws Exception { PhoneNumber invalidPhoneNumber = new PhoneNumber("", "", PhoneTestConstants.US_COUNTRY_CODE); assertFalse(PhoneNumber.isCountryValid(invalidPhoneNumber)); invalidPhoneNumber = new PhoneNumber("", PhoneTestConstants.US_ISO2, ""); assertFalse(PhoneNumber.isCountryValid(invalidPhoneNumber)); }
@Test public void testIsCountryValid() throws Exception { final PhoneNumber validPhoneNumber = new PhoneNumber("", PhoneTestConstants.US_ISO2, PhoneTestConstants.US_COUNTRY_CODE); assertTrue(PhoneNumber.isCountryValid(validPhoneNumber)); }