def each
      return enum_for(:each) unless block_given?

      pointer = self
      loop do
        break if pointer.null?
        yield pointer
        pointer = pointer.next
      end
    end
def each
      return enum_for(:each) unless block_given?

      pointer = self
      loop do
        break if pointer.null?
        yield pointer
        pointer = pointer.next
      end
    end
Exposes the linked list structure in an Enumerable-compatible format