input: def generate_response(question: str) -> str:
      """Generate a response to a user's question based on a predefined set of answers. If the question is not found in the answers, provide a random response.
      >>> 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('Non-existing question')
      'I am not sure I understand.'
      """
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.'
      }
      return predefined_answers.get(question, 'I am not sure I understand.')