code: public final boolean isPhoneNumberEmpty(final PhoneNumberInterface pphoneNumberData) {
      return pphoneNumberData == null || StringUtils.isBlank(pphoneNumberData.getCountryCode())
          || StringUtils.isBlank(pphoneNumberData.getLineNumber());
    }
docs: check if phone number is empty.
  
  @param pphoneNumberData phone number to check
  @return true if number is empty