old_contents: #!/usr/bin/env python3
  from manager import Manager
  
  manager = Manager()
  
  
  @manager.command
  def build(threads=1):
      print("Starting a build with %d threads ..." % threads)
  
  @manager.command
  def clean():
      pass
  
  if __name__ == '__main__':
      manager.main()
  
new_contents: #!/usr/bin/env python3
  from manager import Manager
  from multiprocessing import Pool
  
  manager = Manager()
  
  
  def func(period):
      from time import sleep
      sleep(period)
  
  
  @manager.command
  def build(threads=1):
      pool = Pool(threads)
      print("Starting a build with %d threads ..." % threads)
      pool.map(func, [1, 1, 1, 1, 1])
  
  
  @manager.command
  def clean():
      pass
  
  
  if __name__ == '__main__':
      manager.main()
  
subject: Add parallelizing code to build