code: def test_diffs(self):
      x = tf.constant([1, 2, 3, 4, 5])
      dx = self.evaluate(math.diff(x, order=1, exclusive=False))
      np.testing.assert_array_equal(dx, [1, 1, 1, 1, 1])
  
      dx1 = self.evaluate(math.diff(x, order=1, exclusive=True))
      np.testing.assert_array_equal(dx1, [1, 1, 1, 1])
  
      dx2 = self.evaluate(math.diff(x, order=2, exclusive=False))
      np.testing.assert_array_equal(dx2, [1, 2, 2, 2, 2])
  
file_path: tf-quant-finance/tf_quant_finance/math/diff_ops_test.py
imports: from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  from tf_quant_finance import math
  from tensorflow.python.framework import test_util
label_desc: Use image node_id 1 for calling the DiffOpsTest obj's underlying member method code with example usage: obj.test_diffs() without return types