code: import logging
  
  from langchain.chains import RetrievalQA
  
  from neogpt.prompts.prompt import get_prompt
  
  
  def local_retriever(db, llm, persona="default"):
      """
      Fn: local_retriever
      Description: The function sets up the local retrieval-based question-answering system.
      Args:
          db (object): The database object
          llm (object): The LLM model object
      return:
          chain (object): The chain object
      """
      try:
          prompt, memory = get_prompt(persona=persona)
          # Create a retriever object
          local_retriever = db.as_retriever()
          chain = RetrievalQA.from_chain_type(
              llm=llm,
              retriever=local_retriever,
              chain_type="stuff",
              chain_type_kwargs={"prompt": prompt, "memory": memory},
              return_source_documents=True,
          )
          logging.info("Loaded Local Retriever Successfully 🔍")
      except Exception as e:
          logging.info(f"Error {e}")
  
      return chain
  
apis: langchain.chains.RetrievalQA.from_chain_type
extract_api: [((466, 493), 'neogpt.prompts.prompt.get_prompt', 'get_prompt', ([], {'persona': 'persona'}), '(persona=persona)\n', (476, 493), False, 'from neogpt.prompts.prompt import get_prompt\n'), ((590, 768), 'langchain.chains.RetrievalQA.from_chain_type', 'RetrievalQA.from_chain_type', ([], {'llm': 'llm', 'retriever': 'local_retriever', 'chain_type': '"""stuff"""', 'chain_type_kwargs': "{'prompt': prompt, 'memory': memory}", 'return_source_documents': '(True)'}), "(llm=llm, retriever=local_retriever, chain_type=\n    'stuff', chain_type_kwargs={'prompt': prompt, 'memory': memory},\n    return_source_documents=True)\n", (617, 768), False, 'from langchain.chains import RetrievalQA\n'), ((839, 892), 'logging.info', 'logging.info', (['"""Loaded Local Retriever Successfully 🔍"""'], {}), "('Loaded Local Retriever Successfully 🔍')\n", (851, 892), False, 'import logging\n'), ((928, 954), 'logging.info', 'logging.info', (['f"""Error {e}"""'], {}), "(f'Error {e}')\n", (940, 954), False, 'import logging\n')]