class_docstr: Locking mechanism that issues tickets managing access to conversation IDs.
  
  Tickets are issued in the order in which they are requested. A detailed
  explanation of the ticket lock algorithm can be found at
  http://pages.cs.wisc.edu/~remzi/OSTEP/threads-locks.pdf#page=13
docstr: Remove expired tickets.
docstr_tok: ["Remove","expired","tickets","."]
code: def remove_expired_tickets(self) -> None:
      """Remove expired tickets."""
      # iterate over copy of self.tickets so we can remove items
      for ticket in list(self.tickets):
          if ticket.has_expired():
              self.tickets.remove(ticket)
  
imports: import json
  import logging
  from collections import deque
  import time
  from typing import Text, Optional, Union, Deque, Dict, Any
label_desc: Use image node_id 6 for calling the TicketLock obj's underlying member method code with example usage: obj.remove_expired_tickets() without return types