class_docstr: Helper abc which defines all methods a ParallelBackend must implement
class_docstr_tok: ["Helper","abc","which","defines","all","methods","a","ParallelBackend","must","implement"]
docstr: Schedule a func to be run
code: def apply_async(self, func, callback=None):
      """Schedule a func to be run"""
  
imports: import gc
  import os
  import sys
  import warnings
  import threading
  from abc import ABCMeta, abstractmethod
  from .format_stack import format_exc
  from .my_exceptions import WorkerInterrupt, TransportableException
  from ._multiprocessing_helpers import mp
  from ._compat import with_metaclass
label_desc: Use image node_id 2 for calling the ParallelBackendBase obj's underlying member method code with example usage: obj.apply_async(func, callback) without return types