JDiscContext newestContext() {
        JDiscContext context = contexts.peekFirst();
        if (context == null) throw new IllegalStateException("JettyHttpServer has no registered JDiscContext");
        return context;
    }
@author Simon Thoresen Hult
@author bjorncs
container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/JettyHttpServer.java