public KubernetesEndpointGroup build() {
        checkState(serviceName != null, "serviceName not set");
        return new KubernetesEndpointGroup(kubernetesClient, namespace, serviceName, portName,
                                           nodeAddressFilter, autoClose,
                                           selectionStrategy, shouldAllowEmptyEndpoints(),
                                           selectionTimeoutMillis(), maxWatchAgeMillis);
    }
Returns a newly-created {@link KubernetesEndpointGroup} based on the properties of this builder.
kubernetes/src/main/java/com/linecorp/armeria/client/kubernetes/endpoints/KubernetesEndpointGroupBuilder.java