code: def __lt__(self, other):
      return self.val < other.val
  
file_path: coding-problems/Linked Lists/merge_k_sorted_ll.py
imports: from ll_helpers import ListNode
  import heapq
label_desc: Use image node_id 2 for calling the PQNode obj's underlying member method code with example usage: obj.__lt__(other) and returns: unknown