old_contents: import unittest
  import numpy as np
  from op_test import OpTest
  
  
  class TestPadOp(OpTest):
      def setUp(self):
          self.initTestCase()
          self.op_type = "pad"
          self.inputs = {'X': np.random.random(self.shape).astype("float32"), }
          self.attrs = {}
          self.attrs['paddings'] = np.array(self.paddings).flatten()
          self.attrs['pad_value'] = self.pad_value
          self.outputs = {
              'Out': np.pad(self.inputs['X'],
                            self.paddings,
                            mode='constant',
                            constant_values=self.pad_value)
          }
  
      def test_check_output(self):
          self.check_output()
  
      def test_check_grad_normal(self):
          self.check_grad(['X'], 'Out', max_relative_error=0.5)
  
      def initTestCase(self):
          self.shape = (16, 16)
          self.paddings = [(0, 1), (2, 3)]
          self.pad_value = 0
  
  
  class TestCase1(TestPadOp):
      def initTestCase(self):
          self.shape = (2, 3, 4, 4)
          self.paddings = [(0, 1), (2, 3), (2, 1), (1, 1)]
          self.pad_value = 0.5
  
  
  class TestCase2(TestPadOp):
      def initTestCase(self):
          self.shape = (2, 2, 2)
          self.paddings = [(0, 0), (0, 0), (1, 2)]
          self.pad_value = 1
  
  
  class TestCase3(TestPadOp):
      def initTestCase(self):
          self.shape = (8)
          self.paddings = [(0, 1)]
          self.pad_value = 0.9
  
  
  if __name__ == '__main__':
      unittest.main()
  
new_contents: import unittest
  import numpy as np
  from op_test import OpTest
  
  
  class TestPadOp(OpTest):
      def setUp(self):
          self.initTestCase()
          self.op_type = "pad"
          self.inputs = {'X': np.random.random(self.shape).astype("float32"), }
          self.attrs = {}
          self.attrs['paddings'] = np.array(self.paddings).flatten()
          self.attrs['pad_value'] = self.pad_value
          self.outputs = {
              'Out': np.pad(self.inputs['X'],
                            self.paddings,
                            mode='constant',
                            constant_values=self.pad_value)
          }
  
      def test_check_output(self):
          self.check_output()
  
      def test_check_grad_normal(self):
          self.check_grad(['X'], 'Out', max_relative_error=0.006)
  
      def initTestCase(self):
          self.shape = (16, 16)
          self.paddings = [(0, 1), (2, 3)]
          self.pad_value = 0
  
  
  class TestCase1(TestPadOp):
      def initTestCase(self):
          self.shape = (2, 3, 4, 4)
          self.paddings = [(0, 1), (2, 3), (2, 1), (1, 1)]
          self.pad_value = 0.5
  
  
  class TestCase2(TestPadOp):
      def initTestCase(self):
          self.shape = (2, 2, 2)
          self.paddings = [(0, 0), (0, 0), (1, 2)]
          self.pad_value = 1
  
  
  class TestCase3(TestPadOp):
      def initTestCase(self):
          self.shape = (8)
          self.paddings = [(0, 1)]
          self.pad_value = 0.9
  
  
  if __name__ == '__main__':
      unittest.main()
  
subject: update unitest