input: def generate_response(question: str) -> str:
      """ This function generates a response to a simple query about a product or service.
      It uses a predefined dictionary of answers for known questions and a random response for
      unknown questions. The conversation is then initiated and continues until the user says 'Goodbye'.
      >>> generate_response('What is XYZ?')
      'XYZ is a company that provides XYZ services.'
      >>> generate_response('How do I contact XYZ?')
      'I am not sure I understand.'
      """
output:     known_questions = {
          'What is XYZ?': 'XYZ is a company that provides XYZ services.',
          'How do I contact XYZ?': 'You can contact XYZ through their website or customer service hotline.'
      }
      
      if question in known_questions:
          return known_questions[question]
      else:
          return "I am not sure I understand."