code: def prompt_4_yes_no(question, input = None):
      
      count = 0
      while True:
          printError(question + ' (y/n)? ')
          choice = prompt(input).lower()
          if choice == 'yes' or choice == 'y':
              return True
          elif choice == 'no' or choice == 'n':
              return False
          else:
              count += 1
              printError('\'%s\' is not a valid answer. Enter \'yes\'(y) or \'no\'(n).' % choice)
              if count > 3:
                  return None
docs: Prompt for a yes/no or y/n answer
                                          .
      :param question:                    Question to be asked
      :param input:                       Used for unit testing
  
      :return:                            True for yes/y, False for no/n