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: Return ticket for `ticket_number`.
docstr_tok: ["Return","ticket","for","`","ticket_number","`","."]
code: def _ticket_for_ticket_number(
      self, ticket_number: int
  ) -> Optional[Ticket]:
      """Return ticket for `ticket_number`."""
      self.remove_expired_tickets()
  
      return next(
          (t for t in self.tickets if t.number == ticket_number), None
      )
  
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 10 for calling the TicketLock obj's underlying member method code with example usage: obj._ticket_for_ticket_number(ticket_number) and returns: next