public void TestPredecessor() { Assert.AreEqual(tree.Nil, tree.Predecessor(tree.Minimum(tree.Root))); Assert.AreSame(tree.Nil, tree.Predecessor(tree.Minimum(tree.Root))); Assert.AreEqual(tree.Root.Left.Right, tree.Predecessor(tree.Root)); Assert.AreSame(tree.Root.Left.Right, tree.Predecessor(tree.Root)); Assert.AreEqual(tree.Root.Left.Left, tree.Predecessor(tree.Get(0))); Assert.AreSame(tree.Root.Left.Left, tree.Predecessor(tree.Get(0))); }