Update app.py

app.py

@@ -8,6 +8,9 @@ from llama_index import VectorStoreIndex, SimpleDirectoryReader, ServiceContext
 from llama_index.llms import LlamaCPP
 from llama_index.llms.llama_utils import messages_to_prompt, completion_to_prompt
 from langchain.embeddings.huggingface import HuggingFaceEmbeddings
+from langchain_community.llms import Cohere
+from langchain_community.llms import FakeListLLM
+
 
 # Set up logging
 logging.basicConfig(stream=sys.stdout, level=logging.INFO)