Update utils.py

utils.py

@@ -10,7 +10,7 @@ from   langchain.schema            import StrOutputParser
 from   langchain.utils             import get_from_dict_or_env
 from   langchain.vectorstores      import Chroma
 from   langchain.text_splitter     import RecursiveCharacterTextSplitter
-from   langchain.chains            import RetrievalQA
+from   langchain.chains            import RetrievalQA, MapReduceDocumentsChain, ReduceDocumentsChain
 from   langchain.document_loaders  import TextLoader
 from   langchain.embeddings        import HuggingFaceEmbeddings, OpenAIEmbeddings
 from   langchain.chains            import LLMChain