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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def call_after(lag):
 """ Parametrized decorator for calling a function after a time ``lag`` given in milliseconds. This cancels simultaneous calls. """

  def decorator(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
      wrapper.timer.cancel() # Debounce
      wrapper.timer = threading.Timer(lag, func, args=args, kwargs=kwargs)
      wrapper.timer.start()
    wrapper.timer = threading.Timer(0, lambda: None) # timer.cancel now exists
    return wrapper
  return decorator