public void ToSvg_Failure()
        {
            WebRequest.RegisterPrefix(
                GraphvizExtensions.DotToSvgApiEndpoint,
                new TestWebRequestCreate());
            TestWebRequestCreate.CreateFailTestRequest();

            AdjacencyGraph <int, Edge <int> > graph = CreateTestGraph();

            Assert.IsEmpty(graph.ToSvg());
        }
        public void ToSvgWithInit_Failure()
        {
            WebRequest.RegisterPrefix(
                GraphvizExtensions.DotToSvgApiEndpoint,
                new TestWebRequestCreate());
            TestWebRequestCreate.CreateFailTestRequest();

            AdjacencyGraph <int, Edge <int> > graph = CreateTestGraph();

            Assert.IsEmpty(
                graph.ToSvg(
                    algorithm =>
            {
                algorithm.CommonVertexFormat.ToolTip = "Test vertex";
            }));
        }