public static string GetOwlVersionInfo(this OntologyResource resource)
        {
            if (!resource.HasOwlVersionInfo())
            {
                throw new RdfException($"Resource {resource} does not have an owl:versionInfo annotation");
            }

            INode owlVersionInfo = resource.Graph.CreateUriNode(VocabularyHelper.OWL.versionInfo);

            return(resource.GetNodesViaPredicate(owlVersionInfo).LiteralNodes().First().Value);
        }