improve: introduce isort for linting Python imports (#1983)

api/services/hit_testing_service.py

@@ -4,19 +4,18 @@ import time
 from typing import List
 
 import numpy as np
-from flask import current_app
-from langchain.embeddings.base import Embeddings
-from langchain.schema import Document
-from sklearn.manifold import TSNE
-
 from core.embedding.cached_embedding import CacheEmbedding
 from core.model_manager import ModelManager
 from core.model_runtime.entities.model_entities import ModelType
 from core.rerank.rerank import RerankRunner
 from extensions.ext_database import db
+from flask import current_app
+from langchain.embeddings.base import Embeddings
+from langchain.schema import Document
 from models.account import Account
-from models.dataset import Dataset, DocumentSegment, DatasetQuery
+from models.dataset import Dataset, DatasetQuery, DocumentSegment
 from services.retrieval_service import RetrievalService
+from sklearn.manifold import TSNE
 
 default_retrieval_model = {
     'search_method': 'semantic_search',