The AvlTree.ExtractMax method duplicated the functionality of AvlTree.DeleteMax, so it's been removed.
The AvlTree.DeleteMin method was created (based on AvlTree.DeleteMax) and the AvlTree.ExtractMin method was removed.
AvlTree.TryExtractMax and AvlTree.TryExtractMin have been renamed to TryDeleteMax and TryDeleteMin, respectively.