docstr: Update IOLoop handler with state.
  
  zmq FD is always read-only.
code: def _update_handler(self, state):
      """Update IOLoop handler with state.
  
      zmq FD is always read-only.
      """
      # ensure loop is registered and init_io has been called
      # if there are any events to watch for
      if state:
          self._get_loop()
      self._schedule_remaining_events()
  
imports: import warnings
  from asyncio import Future
  from collections import deque
  from itertools import chain
  from typing import Any, Awaitable, Callable, Dict, List, NamedTuple, Optional, Tuple, Type, TypeVar, Union, cast, overload
  import zmq
  from zmq import EVENTS, POLLIN, POLLOUT
  from zmq._typing import Literal
label_desc: Use image node_id 28 for calling the _AsyncSocket obj's underlying member method code with example usage: obj._update_handler(state) without return types