public Optional<Output<String>> externalID() {
        return Optional.ofNullable(this.externalID);
    }
@return Deprecated. Not all kubelets will set this field. Remove field after 1.13. see: https://issues.k8s.io/61966
sdk/java/src/main/java/com/pulumi/kubernetes/core/v1/inputs/NodeSpecArgs.java