default Principal buildSurrogatePrincipal(final Credential credential, final Principal primaryPrincipal) throws Throwable {
        return buildSurrogatePrincipal(credential, primaryPrincipal, null);
    }
Build surrogate principal principal without a service.

@param credential        the surrogate
@param primaryPrincipal the primary principal
@return the principal
@throws Throwable the throwable
support/cas-server-support-surrogate-core/src/main/java/org/apereo/cas/authentication/SurrogateAuthenticationPrincipalBuilder.java