input: def generate_response(question):
      """Generate a response to a question about XYZ company or service.
      If the question is in the predefined set of answers, return the corresponding answer.
      Otherwise, return a random response indicating uncertainty or a request for more information.
      The conversation continues until the user says 'Goodbye'.
  
      >>> generate_response('What is XYZ?')
      'XYZ is a company that provides XYZ services.'
      >>> generate_response('What does XYZ do?')
      'XYZ helps customers find solutions to their problems.'
      >>> generate_response('Unknown query')
      'I am not sure I understand.'  # or one of the other random responses
      """
output:     predefined_answers = {
          'What is XYZ?': 'XYZ is a company that provides XYZ services.',
          'What does XYZ do?': 'XYZ helps customers find solutions to their problems.',
          'How can I contact XYZ?': 'You can contact XYZ through their website or customer service hotline.'
      }
  
      random_responses = [
          'I am not sure I understand.',
          'Could you please clarify your question?',
          'I need more information to answer that.'
      ]
  
      if question in predefined_answers:
          return predefined_answers[question]
      else:
          import random
          return random.choice(random_responses)