private void SerializeGraph(RDFGraph graph, RDFModelEnums.RDFFormats format)
        {
            // create file path
            DirectoryInfo di = Directory.CreateDirectory("graphs");

            switch (format)
            {
            case RDFModelEnums.RDFFormats.NTriples:
                graph.ToFile(RDFModelEnums.RDFFormats.NTriples, "graphs/NTriples.txt");
                break;

            case RDFModelEnums.RDFFormats.RdfXml:
                graph.ToFile(RDFModelEnums.RDFFormats.RdfXml, "graphs/RdfXml.txt");
                break;

            case RDFModelEnums.RDFFormats.TriX:
                graph.ToFile(RDFModelEnums.RDFFormats.TriX, "graphs/TriX.txt");
                break;

            case RDFModelEnums.RDFFormats.Turtle:
                graph.ToFile(RDFModelEnums.RDFFormats.Turtle, "graphs/Turtle.txt");
                break;
            }
        }
        public static void Convert(RDFModelEnums.RDFFormats formatSource, FileInfo fileSource, RDFModelEnums.RDFFormats formatDestination, FileInfo fileDestination)
        {
            RDFGraph graph = RDFGraph.FromFile(formatSource, fileSource.FullName);

            graph.ToFile(formatDestination, fileDestination.FullName);
        }