protected List<Verification.Channel> determineVerificationChannels(final Principal principal, final WebApplicationService service) {
        return properties.getCore().getVerificationChannels()
            .stream()
            .map(name -> name.trim().toUpperCase(Locale.ENGLISH))
            .map(Verification.Channel::valueOf)
            .toList();
    }
This is {@link CasDefaultTwilioMultifactorAuthenticationService}.

@author Misagh Moayyed
@since 7.2.0
support/cas-server-support-twilio-mfa/src/main/java/org/apereo/cas/mfa/twilio/CasDefaultTwilioMultifactorAuthenticationService.java