class_docstr: Manages the communication between this process and the worker processes.
  
  The manager is run in a local thread.
  
  Args:
      executor: A reference to the ProcessPoolExecutor that owns
          this thread. A weakref will be own by the manager as well as
          references to internal objects used to introspect the state of
          the executor.
class_docstr_tok: ["Manages","the","communication","between","this","process","and","the","worker","processes",".","The","manager","is","run","in","a","local","thread",".","Args",":","executor",":","A","reference","to","the","ProcessPoolExecutor","that","owns","this","thread",".","A","weakref","will","be","own","by","the","manager","as","well","as","references","to","internal","objects","used","to","introspect","the","state","of","the","executor","."]
code: def add_call_item_to_queue(self):
      # Fills call_queue with _WorkItems from pending_work_items.
      # This function never blocks.
      while True:
          if self.call_queue.full():
              return
          try:
              work_id = self.work_ids_queue.get(block=False)
          except queue.Empty:
              return
          else:
              work_item = self.pending_work_items[work_id]
  
              if work_item.future.set_running_or_notify_cancel():
                  self.call_queue.put(
                      _CallItem(
                          work_id,
                          work_item.fn,
                          work_item.args,
                          work_item.kwargs,
                      ),
                      block=True,
                  )
              else:
                  del self.pending_work_items[work_id]
                  continue
  
imports: import os
  from concurrent.futures import _base
  import queue
  import multiprocessing
  import multiprocessing.connection
  from multiprocessing.queues import Queue
  import threading
  import weakref
  from functools import partial
  import itertools
  import sys
  from traceback import format_exception
label_desc: Use image node_id 3 for calling the _ExecutorManagerThread obj's underlying member method code with example usage: obj.add_call_item_to_queue() without return types