new_contents: class Timer:
  
      def __init__(self, duration, *callbacks):
          self.duration = duration
          self.callbacks = list(callbacks)
  
          self.elapsed = 0
          self.paused = False
  
      def register(self, callback):
          self.callbacks.append(callback)
  
      def unregister(self, callback):
          self.callbacks.remove(callback)
  
      def pause(self):
          self.paused = True
  
      def unpause(self):
          self.pause = False
  
      def update(self, time):
  
          if self.elapsed > self.duration:
              return
  
          self.elapsed += time
  
          if self.elapsed > self.duration:
  
              for callback in self.callbacks:
                  callback()
  
  
  
subject: Create a timer class in the utilities module.