text: Title: Questions about the train function
  Body: Thanks for the great work.
  I have several questions about the instruct train function
  1. May I know that what vectorDB perform during the train? Does it act as a RAG?
  2. After the train, is that anyway to save the trained model or stuff? Or it requires to call the train function for the prompt everytime?
  3. For the cache, it seems generate a new one when I restart the kernel. Is that it store the previous prompt and response?
  Thank you very much.