old_contents: class Display():
      
      def __init__(self):
          self.start = "Welcome"
          self.draw = "Draw"
          self.computer = "Computer Wins"
          self.human = "You Win"
          self.next_move = "What is your next move?"
  
      def show(self, text):
          print text
  
new_contents: class Display():
      
      def __init__(self):
          self.start = "Welcome"
          self.draw = "Draw"
          self.computer = "Computer Wins"
          self.human = "You Win"
          self.next_move = "What is your next move?"
          self.bad_move = "That is not a legal move."
  
      def show(self, text):
          print text
  
subject: add illegal move message to display