code: def oddEvenList(self, head):
      """
      :type head: ListNode
      :rtype: ListNode
      """
      odd = head
      if head is None:
          return None
      if head.next is None:
          return head
      even_head = even = head.next
      while odd.next is not None and even.next is not None:
          odd.next = even.next
          odd = odd.next
          even.next = odd.next
          even = even.next
      odd.next = even_head
      return head
  
label_desc: Use image node_id 1 for calling the Solution obj's underlying member method code with example usage: obj.oddEvenList(head) and returns: head, None, head