public void TreeWithBookPreorder(Book[] array, Book[] result, IComparer<Book> comparer) { var tree = new BinaryTree<Book>(array, comparer); var enumeratorBook = tree.GetEnumerator(); var enumeratorResult = result.GetEnumerator(); while (enumeratorBook.MoveNext() && enumeratorResult.MoveNext()) { Assert.AreEqual(enumeratorResult.Current, enumeratorBook.Current); } }