code: def verification_checks(self):
          
          if self._verification_checks is None:
              self._verification_checks = VerificationCheckList(self._version, service_sid=self._solution['sid'], )
          return self._verification_checks
docs: Access the verification_checks
  
          :returns: twilio.rest.preview.acc_security.service.verification_check.VerificationCheckList
          :rtype: twilio.rest.preview.acc_security.service.verification_check.VerificationCheckList