old_contents: # Copyright 2009 Brian Quinlan. All Rights Reserved.
  # Licensed to PSF under a Contributor Agreement.
  
  """Execute computations asynchronously using threads or processes."""
  
  __author__ = 'Brian Quinlan (brian@sweetapp.com)'
  
  from concurrent.futures._base import (FIRST_COMPLETED,
                                        FIRST_EXCEPTION,
                                        ALL_COMPLETED,
                                        CancelledError,
                                        TimeoutError,
                                        Future,
                                        Executor,
                                        wait,
                                        as_completed)
  from concurrent.futures.thread import ThreadPoolExecutor
  import sys
  
  try:
      from concurrent.futures.process import ProcessPoolExecutor
  except ImportError:
      # Jython doesn't have multiprocessing
      if not sys.platform.startswith('java'):
          raise
  
new_contents: # Copyright 2009 Brian Quinlan. All Rights Reserved.
  # Licensed to PSF under a Contributor Agreement.
  
  """Execute computations asynchronously using threads or processes."""
  
  __author__ = 'Brian Quinlan (brian@sweetapp.com)'
  
  from concurrent.futures._base import (FIRST_COMPLETED,
                                        FIRST_EXCEPTION,
                                        ALL_COMPLETED,
                                        CancelledError,
                                        TimeoutError,
                                        Future,
                                        Executor,
                                        wait,
                                        as_completed)
  from concurrent.futures.thread import ThreadPoolExecutor
  import sys
  
  try:
      from concurrent.futures.process import ProcessPoolExecutor
  except ImportError:
      # some platforms don't have multiprocessing
      pass
  
subject: Make multiprocessing optional, again