public void Add_NewStudentNodeToPrevious_ShouldPutNewNodeToRightSideOfPrevious()
        {
            //act
            nodeStudent_10.Add(nodeStudent_20);

            //assert

            Assert.AreEqual(nodeStudent_10.LeftNode, null);
            Assert.AreEqual(nodeStudent_10.RightNode, nodeStudent_20);
        }
        public void GetDataByForeach_BinaryTree_10_4_12_Return_4_10_12()
        {
            //arrange
            BinaryTreeNode <int> binaryTree = new BinaryTreeNode <int>(10);

            binaryTree.Add(new BinaryTreeNode <int>(4));
            binaryTree.Add(new BinaryTreeNode <int>(12));

            // act

            string result = string.Empty;

            foreach (int item in binaryTree)
            {
                result += item;
            }

            //assert

            Assert.AreEqual(result, "41012");
        }
        public void Add_NewIntNodeToPrevious_ShouldPutNewNodeToRightSideOfPrevious()
        {
            //arrange

            BinaryTreeNode <int> binaryTree = new BinaryTreeNode <int>(10);

            BinaryTreeNode <int> node = new BinaryTreeNode <int>(20);

            // act

            binaryTree.Add(node);

            //assert

            Assert.AreEqual(binaryTree.LeftNode, null);
            Assert.AreEqual(binaryTree.RightNode, node);
        }