[keycloak-user] How to obtain identity information from KeycloakSecurityContext

[keycloak demo]

I want to provide access to a resource if the current user is the creator
of resource. So I want to extract identity information. I have
obtained  *KeycloakSecurityContext
*and *AuthorizationContext *from the request.

KeycloakSecurityContext keycloakSecurityContext = (KeycloakSecurityContext)
request.getAttribute(KeycloakSecurityContext.class.getName());
AuthorizationContext authzContext =
keycloakSecurityContext.getAuthorizationContext();

*How can I obtain identity information like mentioned in EvaluationContext**
?*(
https://www.keycloak.org/docs/4.3/authorization_services/#using-the-authorizationcontext-to-obtain-an-authorization-client-instance
)?