public void MemberCurrentRented()
        {
            if (LeftNode != null)
            {
                LeftNode.MemberCurrentRented();
            }

            //Then we print the root node
            Console.WriteLine("Title: {0} Copies Currently Borrowed: {1}", this.Title.PadRight(20), this.NumberOfCopiesRentedByThisUser);

            //Then we go to the right node which will print itself as both its children are null
            if (RightNode != null)
            {
                RightNode.MemberCurrentRented();
            }
        }