old_contents: import functools, threading
  
  
  def compose_events(events, condition=all):
      """Compose a sequence of events into one event.
      Arguments:
          events:    a sequence of objects looking like threading.Event
          condition: a function taking a sequence of bools and returning a bool.
      """
      events = list(events)
      master_event = threading.Event()
  
      def changed():
          if condition(e.is_set() for e in events):
              master_event.set()
          else:
              master_event.clear()
  
      def add_changed(f):
          @functools.wraps(f)
          def wrapped():
              f()
              changed()
          return wrapped
  
      for e in events:
          e.set = add_changed(e.set)
          e.clear = add_changed(e.clear)
  
      changed()
      return master_event
  
new_contents: import functools, threading
  
  
  def compose_events(events, condition=all):
      """Compose a sequence of events into one event.
      Arguments:
          events:    a sequence of objects looking like threading.Event
          condition: a function taking a sequence of bools and returning a bool.
      """
      events = list(events)
      master_event = threading.Event()
  
      def changed():
          if condition(e.is_set() for e in events):
              master_event.set()
          else:
              master_event.clear()
  
      def add_changed(f):
          @functools.wraps(f)
          def wrapped():
              f()
              changed()
  
          return wrapped
  
      for e in events:
          e.set = add_changed(e.set)
          e.clear = add_changed(e.clear)
  
      changed()
      return master_event
  
subject: Add an empty line for style