private static void Validate <T>(BinaryTreeNode <T> expected, BinaryTreeNode <T> a, BinaryTreeNode <T> b)
where T : IEquatable <T>
{
var result = Question_4_8.FindCommonAncestor(a, b);
Assert.AreEqual(expected.Data, result.Data);
}
public void Question_4_8_InvalidCases()
{
TestHelpers.AssertExceptionThrown(() => Question_4_8.FindCommonAncestor(null, new BinaryTreeNode <int>(1)), typeof(ArgumentNullException));
TestHelpers.AssertExceptionThrown(() => Question_4_8.FindCommonAncestor(new BinaryTreeNode <int>(1), null), typeof(ArgumentNullException));
}
