public void setAccessControl(AccessControl accessControl) {
            if (this.accessControl != null) throw new IllegalStateException("Access control already assigned");
            this.accessControl = accessControl;
    }
Represents the http servers and filters of a container cluster.

@author Tony Vaagenes
@author bjorncs
config-model/src/main/java/com/yahoo/vespa/model/container/http/Http.java