old_contents: #  Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserve.
  #
  #Licensed under the Apache License, Version 2.0 (the "License");
  #you may not use this file except in compliance with the License.
  #You may obtain a copy of the License at
  #
  #    http://www.apache.org/licenses/LICENSE-2.0
  #
  #Unless required by applicable law or agreed to in writing, software
  #distributed under the License is distributed on an "AS IS" BASIS,
  #WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  #See the License for the specific language governing permissions and
  #limitations under the License.
  import unittest
  import numpy as np
  from op_test import OpTest
  
  
  def sequence_erase(in_seq, lod0, tokens):
      new_lod0 = [0]
      out_seq = []
      for i in range(0, len(lod0) - 1):
          num_out = 0
          for dat in in_seq[lod0[i]:lod0[i + 1]]:
              if dat not in tokens:
                  out_seq.append(dat)
                  num_out += 1
          new_lod0.append(new_lod0[-1] + num_out)
      return np.array(out_seq).astype("int32"), new_lod0
  
  
  class TestSequenceEraseOp(OpTest):
      def setUp(self):
          self.op_type = "sequence_erase"
          in_seq = np.random.randint(0, 10, (30, 1)).astype("int32")
          lod = [[0, 9, 13, 24, 30]]
          tokens = [2, 3, 5]
          out_seq, new_lod0 = sequence_erase(in_seq, lod[0], tokens)
          self.attrs = {'tokens': tokens}
          self.inputs = {'X': (in_seq, lod)}
          self.outputs = {'Out': (out_seq, [new_lod0])}
  
      def test_check_output(self):
          self.check_output()
  
  
  if __name__ == '__main__':
      unittest.main()
  
new_contents: #  Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserve.
  #
  #Licensed under the Apache License, Version 2.0 (the "License");
  #you may not use this file except in compliance with the License.
  #You may obtain a copy of the License at
  #
  #    http://www.apache.org/licenses/LICENSE-2.0
  #
  #Unless required by applicable law or agreed to in writing, software
  #distributed under the License is distributed on an "AS IS" BASIS,
  #WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  #See the License for the specific language governing permissions and
  #limitations under the License.
  import unittest
  import numpy as np
  from op_test import OpTest
  
  
  def sequence_erase(in_seq, lod0, tokens):
      new_lod0 = [0]
      out_seq = []
      for i in range(0, len(lod0) - 1):
          num_out = 0
          for dat in in_seq[lod0[i]:lod0[i + 1]]:
              if dat not in tokens:
                  out_seq.append(dat)
                  num_out += 1
          new_lod0.append(new_lod0[-1] + num_out)
      return np.array(out_seq).astype("int32"), new_lod0
  
  
  class TestSequenceEraseOp(OpTest):
      def setUp(self):
          self.op_type = "sequence_erase"
          in_seq = np.random.randint(0, 10, (30, 1)).astype("int32")
          lod = [[0, 9, 13, 24, 30]]
          tokens = [2, 3, 5]
          out_seq, new_lod0 = sequence_erase(in_seq, lod[0], tokens)
          self.attrs = {'tokens': tokens}
          self.inputs = {'X': (in_seq, lod)}
          self.outputs = {'Out': (out_seq, [new_lod0])}
  
      def test_check_output(self):
          self.check_output()
  
  
  class TestSequenceEraseOpEmpty(OpTest):
      def setUp(self):
          self.op_type = "sequence_erase"
          in_seq = np.random.randint(0, 10, (30, 1)).astype("int32")
          lod = [[0, 9, 13, 24, 30]]
          tokens = []
          out_seq, new_lod0 = sequence_erase(in_seq, lod[0], tokens)
          self.attrs = {'tokens': tokens}
          self.inputs = {'X': (in_seq, lod)}
          self.outputs = {'Out': (out_seq, [new_lod0])}
  
      def test_check_output(self):
          self.check_output()
  
  
  if __name__ == '__main__':
      unittest.main()
  
subject: Add unit test case for no tokens to be erased