   // post: asks the user a question, forcing an answer of "y" or "n";
   //       returns true if the answer was yes, returns false otherwise
   public boolean yesTo(String prompt) {
      System.out.print(prompt + " (y/n)? ");
      String response = console.nextLine().trim().toLowerCase();
      while (!response.equals("y") && !response.equals("n")) {
         System.out.println("Please answer y or n.");
         System.out.print(prompt + " (y/n)? ");
         response = console.nextLine().trim().toLowerCase();
      }
      return response.equals("y");
   }
