public void FindNextPrev_CheckValue()
{
ITree tree = new RBTree();
for (int i = 0; i < Nodes.Length; i++)
{
tree.AddNode(Nodes[i]);
}
Assert.AreEqual(20, tree.FindNextNode(19).Value);
Assert.AreEqual(19, tree.FindPrevNode(20).Value);
Assert.AreEqual(null, tree.FindPrevNode(19));
Assert.AreEqual(26, tree.FindNextNode(23).Value);
Assert.AreEqual(20, tree.FindPrevNode(23).Value);
}