OAUTH2 OPENID Connect Fediz implementation.

Hi.

I'm making an implementation of CXF with OpenId connect. I have been able that the Oauth2 authorization code flow works. but i have been unable with the OpenIdConnect because there's not enought documentation and examples to implement it. at least i have not found it. I'm trying something that in the apache web page explains as fediz but i dont know how to implement it. I have look for the java code. And i have seen that Fediz is always using an interface called FedizPrincipal. The code is validating in
org.apache.cxf.fediz.service.oidc.FedizSubjectCreator.

Principal principal = mc.getSecurityContext().getUserPrincipal();
if (!(principal instanceof FedizPrincipal)) {
throw new OAuthServiceException("Unsupported Principal");
}

but i have not seen any kind of implementation of that interface.
i need some example of implementation of that interface or known if i'm in the wrong way.

Please any help would be appreciated.
Regards.

Oscar.