diff --git a/python/orca/test/bigdl/orca/learn/ray/tf/test_tf_ray_estimator.py b/python/orca/test/bigdl/orca/learn/ray/tf/test_tf_ray_estimator.py
index 5127673dcb1..15ddd998adf 100644
--- a/python/orca/test/bigdl/orca/learn/ray/tf/test_tf_ray_estimator.py
+++ b/python/orca/test/bigdl/orca/learn/ray/tf/test_tf_ray_estimator.py
@@ -59,7 +59,8 @@ def create_test_dataset(config):
 
 def simple_model(config):
     import tensorflow as tf
-    model = tf.keras.models.Sequential([tf.keras.layers.Dense(10, input_shape=(1,)), tf.keras.layers.Dense(1)])
+    model = tf.keras.models.Sequential([tf.keras.layers.Dense(10, input_shape=(1,)),
+                                        tf.keras.layers.Dense(1)])
     return model