class_docstr: Class to wrap Langchain LLMs and make PandasAI interoperable
  with LangChain.
code: def type(self) -> str:
      return f"langchain_{self._langchain_llm._llm_type}"
  
imports: from pandasai.prompts.base import AbstractPrompt
  from .base import LLM
label_desc: Use image node_id 3 for calling the LangchainLLM obj's underlying member method code with example usage: obj.type() and returns: str, self