code: def echo(message, history, system_prompt, tokens):
      response = f"System prompt: {system_prompt}\n Message: {message}."
      for i in range(min(len(response), int(tokens))):
          time.sleep(0.05)
          yield response[: i + 1]
  
label_desc: Use image node_id 1 for calling a global function with example usage: echo(message, history, system_prompt, tokens) without return types