class_docstr: Subscribe to a Publish/Subscribe topic
  
  See Also
  --------
  Pub: for full docstring
docstr: Get a single message
  
  Parameters
  ----------
  timeout : number or string or timedelta, optional
      Time in seconds to wait before timing out.
      Instead of number of seconds, it is also possible to specify
      a timedelta in string format, e.g. "200ms".
docstr_tok: ["Get","a","single","message","Parameters","--","--","--","--","--","timeout",":","number","or","string","or","timedelta",",","optional","Time","in","seconds","to","wait","before","timing","out",".","Instead","of","number","of","seconds",",","it","is","also","possible","to","specify","a","timedelta","in","string","format",",","e.g",".","``","200ms","''","."]
code: def get(self, timeout=None):
      """Get a single message
  
      Parameters
      ----------
      timeout : number or string or timedelta, optional
          Time in seconds to wait before timing out.
          Instead of number of seconds, it is also possible to specify
          a timedelta in string format, e.g. "200ms".
      """
      timeout = parse_timedelta(timeout)
      if self.client:
          return self.client.sync(self._get, timeout=timeout)
      elif self.worker.thread_id == threading.get_ident():
          return self._get()
      else:
          if self.buffer:  # fastpath
              return self.buffer.popleft()
          return sync(self.loop, self._get, timeout=timeout)
  
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 3 for calling the Sub obj's underlying member method code with example usage: obj.get(timeout) and returns: self, self, sync, self