IDToken idToken = new IDToken();
idToken.setEmail("joe@email.cz");
KeyPair keyPair = KeyPairGenerator.getInstance("RSA").generateKeyPair();
String encoded = new JWSBuilder()
.jsonContent(token)
.rsa256(keyPair.getPrivate());
String encodedIdToken = new JWSBuilder()
.jsonContent(idToken)
.rsa256(keyPair.getPrivate());
KeycloakSecurityContext ctx = new KeycloakSecurityContext(encoded, token, encodedIdToken, idToken);
KeycloakPrincipal principal = new KeycloakPrincipal("joe", ctx);