ValidationError: 1 validation error for NodeWithScore node Can't instantiate abstract class BaseNode with abstract methods get_content, get_metadata_str, get_type, hash, set_content (type=type_error)
import streamlit as st from llama_index.llms.openai import OpenAI from llama_index.retrievers.bm25 import BM25Retriever from llama_index.core.retrievers import VectorIndexRetriever from llama_index.core.retrievers import BaseRetriever from llama_index.core.chat_engine import CondensePlusContextChatEngine from llama_index.core.query_engine import RetrieverQueryEngine from llama_index.core.postprocessor import LongContextReorder from llama_index.core.base.llms.types import ChatMessage, MessageRole from llama_index.embeddings.openai import OpenAIEmbedding import openai import os
