class_docstr: ListNode Class
code: def __init__(self, val):
      self.val = val
      self.next = None
  
imports: from heapq import heappop, heapreplace, heapify
  from queue import PriorityQueue
label_desc: Use image node_id 1 to create a new ListNode object from inherited base classes: object with example: obj = ListNode(val)