public void BFSTest()
        {
            Init();

            foreach (IExtendedGraph graph in graphs)
            {
                graph.AddVertex(1);
                graph.AddVertex(2);
                graph.AddVertex(3);
                graph.AddVertex(4);
                graph.AddEdge(1, 2);
                graph.AddEdge(2, 3);
                graph.AddEdge(3, 4);

                Dictionary <int, int> result = graph.BFS(1);

                Assert.AreEqual(0, result[1]);
                Assert.AreEqual(1, result[2]);
                Assert.AreEqual(2, result[3]);
                Assert.AreEqual(3, result[4]);

                result = graph.BFS(3);
                Assert.AreEqual(0, result[3]);
                Assert.AreEqual(1, result[4]);
                Assert.AreEqual(2, result.Count);

                graph.RemoveVertex(3);
                result = graph.BFS(1);
                Assert.AreEqual(0, result[1]);
                Assert.AreEqual(1, result[2]);
                Assert.AreEqual(2, result.Count);
            }
        }