new_contents: class Display(object):
      """
      The display class is responsible for putting text on the screen. It can
      also be disabled to prevent messages being displayed after an event has
      occured that should not be followed by another message. The enabled
      attribute is shared across all instance of the display.
      """
  
      _shared_state = {}
  
      def __init__(self):
          self.__dict__ = self._shared_state
          self.enabled = True
  
      def enable(self):
          self.enabled = True
  
      def disable(self):
          self.enabled = False
  
      def write(self, msg):
          print(msg)
  
subject: Add basic display class