public void TestContains()
{
GeneralTree <int> t = GetTestTree();
Assert.AreEqual(t.Contains(5), true);
Assert.AreEqual(t.Contains(2), true);
Assert.AreEqual(t.Contains(3), true);
Assert.AreEqual(t.Contains(1), true);
Assert.AreEqual(t.Contains(9), true);
Assert.AreEqual(t.Contains(12), true);
Assert.AreEqual(t.Contains(13), true);
Assert.AreEqual(t.Contains(4), false);
}
