diff --git a/csst_common/data_manager.py b/csst_common/data_manager.py
index 45a0f72b2542ca8a6e3500ee63e66358cd03b9be..a4874d37fc8c5ec123123f308655bd6cf1576acd 100644
--- a/csst_common/data_manager.py
+++ b/csst_common/data_manager.py
@@ -18,7 +18,6 @@ import os
 import re
 from typing import Union
 
-import joblib
 import numpy as np
 from astropy.io import fits
 from astropy.table import Table
@@ -693,6 +692,8 @@ def test_dm():
     import joblib
     from csst_common.data_manager import CsstMsDataManager
     dm = CsstMsDataManager(dfs_node="pml")
+
     def f(dm, a=1):
         print(a)
-    joblib.Parallel(n_jobs=10,)(joblib.delayed(f)(dm) for i in range(10))
+
+    joblib.Parallel(n_jobs=10, )(joblib.delayed(f)(dm) for i in range(10))