class_docstr: Extend Dask's scheduler with routes to handle PubSub machinery
code: def remove_publisher(self, name=None, worker=None):
      if worker in self.publishers[name]:
          logger.debug("Remove publisher: %s %s", name, worker)
          self.publishers[name].remove(worker)
  
          if not self.subscribers[name] and not self.publishers[name]:
              del self.subscribers[name]
              del self.publishers[name]
  
imports: from __future__ import annotations
  import asyncio
  import logging
  import threading
  import weakref
  from collections import defaultdict, deque
  from dask.utils import parse_timedelta
  from distributed.core import CommClosedError
  from distributed.metrics import time
  from distributed.protocol.serialize import to_serialize
  from distributed.utils import TimeoutError, sync, wait_for
label_desc: Use image node_id 4 for calling the PubSubSchedulerExtension obj's underlying member method code with example usage: obj.remove_publisher(name, worker) without return types