@Override
    public String resolveThemeName(final HttpServletRequest request) {
        return tenantExtractor.getObject()
            .extract(request)
            .map(TenantDefinition::getUserInterfacePolicy)
            .filter(policy -> StringUtils.isNotBlank(policy.getThemeName()))
            .map(TenantUserInterfacePolicy::getThemeName)
            .orElseGet(this::getDefaultThemeName);
    }
This is {@link TenantThemeResolver}.

@author Misagh Moayyed
@since 7.3.0
core/cas-server-core-multitenancy/src/main/java/org/apereo/cas/multitenancy/TenantThemeResolver.java