code: def dependent_phone_numbers(self):
          
          if self._dependent_phone_numbers is None:
              self._dependent_phone_numbers = DependentPhoneNumberList(
                  self._version,
                  account_sid=self._solution['account_sid'],
                  address_sid=self._solution['sid'],
              )
          return self._dependent_phone_numbers
docs: Access the dependent_phone_numbers
  
          :returns: twilio.rest.api.v2010.account.address.dependent_phone_number.DependentPhoneNumberList
          :rtype: twilio.rest.api.v2010.account.address.dependent_phone_number.DependentPhoneNumberList