@Override
    protected Event doExecuteInternal(final RequestContext requestContext) {
        val authentication = WebUtils.getAuthentication(requestContext);
        val principal = authentication.getPrincipal();
        val accounts = multifactorAuthenticationDeviceManager.findRegisteredDevices(principal);
        val currentAccounts = MultifactorAuthenticationWebflowUtils.getMultifactorAuthenticationRegisteredDevices(requestContext);
        FunctionUtils.doIfNotNull(currentAccounts, __ -> accounts.addAll(currentAccounts));
        MultifactorAuthenticationWebflowUtils.putMultifactorAuthenticationRegisteredDevices(requestContext, new HashSet<>(accounts));
        return null;
    }
This is {@link DefaultMultifactorAuthenticationDeviceProviderAction}.

@author Misagh Moayyed
@since 6.6.0
core/cas-server-core-webflow-mfa-api/src/main/java/org/apereo/cas/web/flow/actions/DefaultMultifactorAuthenticationDeviceProviderAction.java