public void IsCyclic_False_03()
        {
            var n1 = new GraphNode("1");
            var n2 = new GraphNode("2");
            var n3 = new GraphNode("3");
            n1.Neighbors = new[] { n2, n3 };
            n2.Neighbors = new[] { n3 };
            var graph = new Graph(new[] { n1, n2, n3 });

            Assert.IsFalse(graph.IsCyclic());
        }
        public void IsCyclic_True_02()
        {
            var n1 = new GraphNode("1");
            var n2 = new GraphNode("2");
            var n3 = new GraphNode("3");
            n1.Neighbors = new[] { n2 };
            n2.Neighbors = new[] { n3 };
            n3.Neighbors = new[] { n1 };
            var graph = new Graph(new[] { n1, n2, n3 });

            Assert.IsTrue(graph.IsCyclic());
        }