public void TestMethod2()
        {
            var adr = "..\\..\\..\\test_inputs\\test1.dot";
            Func <string, Tuple <string, string>[], string> f = (v, attrs) => v;
            Func <string, string, Tuple <string, string>[], SUndirectedEdge <string> > f2 = (v1, v2, attrs) => new SUndirectedEdge <string>(v1, v2);
            var g2 = BidirectionalGraph <string, SUndirectedEdge <string> > .LoadDotFile(adr, f, f2);

            Assert.AreEqual(4, g2.EdgeCount);
            Assert.AreEqual(5, g2.VertexCount);
        }