diff --git a/README.md b/README.md
index 567d760..a83a693 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,9 @@ This operator can compare two ordered sequences, then detect the range which fea
 
 
 ```python
+import towhee
+import numpy as np
+
 # simulate a video feature by 10 frames of 512d vectors.  
 videos_embeddings = np.random.randn(10,512)
 videos_embeddings = videos_embeddings / np.linalg.norm(videos_embeddings,axis=1).reshape(10,-1)
diff --git a/tn.py b/tn.py
index b0aacf0..c4785eb 100644
--- a/tn.py
+++ b/tn.py
@@ -16,7 +16,7 @@ import numpy as np
 import networkx as nx
 from networkx.algorithms.dag import dag_longest_path
 from typing import List
-from towhee.operator.base import NNOperator, OperatorFlag
+from towhee.operator.base import Operator, OperatorFlag
 from towhee.types.arg import arg, to_image_color
 from towhee import register
 
@@ -184,14 +184,14 @@ def tn(sims: np.ndarray,
 
 
 @register(output_schema=['vec'])
-class TemporalNetwork(NNOperator):
+class TemporalNetwork(Operator):
     """
     TemporalNetwork
     """
     def __init__(self, 
        tn_max_step: int = 10, tn_top_k: int = 5, max_path: int = 10,
         min_sim: float = 0.2, min_length: int = 5, max_iou: float = 0.3):
-
+        super().__init__()
         self._tn_max_step = tn_max_step
         self._tn_top_k = tn_top_k
         self._max_path = max_path