code: def test_sum_abs_diff(self):
      np.testing.assert_almost_equal(sum_abs_diff(const0), 0.0)
      np.testing.assert_almost_equal(sum_abs_diff(const1), 0.0)
      np.testing.assert_almost_equal(sum_abs_diff(constNeg), 0.0)
      np.testing.assert_almost_equal(sum_abs_diff(constF), 0.0)
      np.testing.assert_almost_equal(sum_abs_diff(lin), 19)
      np.testing.assert_almost_equal(
          sum_abs_diff(lin0), 20.0, decimal=5
      )
      np.testing.assert_almost_equal(
          sum_abs_diff(wave), 19.968589240921872, decimal=5
      )
      np.testing.assert_almost_equal(
          sum_abs_diff(offsetWave), 19.968589240921872, decimal=5
      )
      np.testing.assert_almost_equal(
          sum_abs_diff(noiseWave), 106.89552650258346, decimal=5
      )
  
imports: import unittest
  import numpy
  from tsfel.feature_extraction.features import *
label_desc: Use image node_id 26 for calling the TestFeatures obj's underlying member method code with example usage: obj.test_sum_abs_diff() without return types