@Override
    public void serverStarted(Server server) throws Exception {
        // Ensure that the following work will be done once.
        if (completed.compareAndSet(false, true)) {
            final ServerPort activePort = server.activePort();
            assert activePort != null;
            builder.setSchemeAndPortIfAbsent(activePort);
            assert builder.scheme() != null;
            config = new SamlPortConfig(builder.scheme(), builder.port());
            future.complete(config);
        }
    }
Returns whether a {@link SamlPortConfig} has been configured.
saml/src/main/java/com/linecorp/armeria/server/saml/SamlPortConfigAutoFiller.java