public void KeyValueNode_returns_descendantAndSelf_nodes(KeyValueNode <string, int> root)
        {
            // ACT

            var result = root.DescendantsAndSelf().ToArray();

            // ASSERT

            Assert.False(result.ElementAt(0).HasKey);
            Assert.Equal(new[] { "leftNode", "rightNode", "leftLeaf", "leftRightLeaf", "rightRightLeaf" }, result.Skip(1).Select(n => n.Key));
        }