protected HttpAction unauthorized(final CallContext ctx, final List<Client> currentClients) {
        return HttpActionHelper.buildUnauthenticatedAction(ctx.webContext());
    }
Return an unauthorized error.

@param ctx the context
@param currentClients the current clients
@return an unauthorized error
pac4j-core/src/main/java/org/pac4j/core/engine/DefaultSecurityLogic.java