code: def test_slope(self):
      np.testing.assert_almost_equal(slope(const0), 0.0)
      np.testing.assert_almost_equal(
          slope(const1), -8.935559365603017e-18
      )
      np.testing.assert_almost_equal(
          slope(constNeg), 8.935559365603017e-18
      )
      np.testing.assert_almost_equal(
          slope(constF), 1.7871118731206033e-17
      )
      np.testing.assert_almost_equal(slope(lin), 1.0)
      np.testing.assert_almost_equal(slope(lin0), 1.0526315789473686)
      np.testing.assert_almost_equal(
          slope(wave), -0.0003819408289180587
      )
      np.testing.assert_almost_equal(
          slope(offsetWave), -0.00038194082891805853
      )
      np.testing.assert_almost_equal(
          slope(noiseWave), -0.00040205425841671337
      )
  
imports: import unittest
  import numpy
  from tsfel.feature_extraction.features import *
label_desc: Use image node_id 32 for calling the TestFeatures obj's underlying member method code with example usage: obj.test_slope() without return types