input: 
  def generate_natural_language_response(utterance: str) -> str:
      """Generate a natural language response for a given utterance using a pre-trained neural network model.
  
      >>> generate_natural_language_response("What time is it?")
      [[0.1, 0.3, 0.2, 0.4, 0.0]]
      """
  
output:     model = load_pretrained_model()
      response = model.generate_response(utterance)
      return response