old_contents: """
      queueing.kiosk
      ==============
  
      Logic for checkout kiosks.
  
      :author: Michael Browning
      :copyright: (c) 2013 by Michael Browning.
      :license: BSD, see LICENSE for more details.
  """
  
  import threading
  import Queue
  
  
  class Kiosk(threading.Thread):
      """A kiosk that customers check out at."""
  
      def __init__(self, line, kiosk_id=None):
          super(Kiosk, self).__init__()
          self.line = line
          self.id = kiosk_id
          self.daemon = True
  
      def run(self):
          while True:
              try:
                  customer = self.line.get()
                  print 'Customer %d at kiosk %d.' % (customer.id, self.id)
                  customer.checkout()
              except Queue.Empty:
                  pass
  
new_contents: """
      queueing.kiosk
      ==============
  
      Logic for checkout kiosks.
  
      :author: Michael Browning
      :copyright: (c) 2013 by Michael Browning.
      :license: BSD, see LICENSE for more details.
  """
  
  import threading
  import Queue
  
  
  class Kiosk(threading.Thread):
      """A kiosk that customers check out at."""
  
      def __init__(self, line, kiosk_id):
          super(Kiosk, self).__init__()
          self.line = line
          self.id = kiosk_id
          self.daemon = True
  
      def run(self):
          while True:
              try:
                  customer = self.line.get()
                  print 'Customer %d at kiosk %d.' % (customer.id, self.id)
                  customer.checkout()
              except Queue.Empty:
                  pass
  
subject: Remove default value for kiosk_id in init