code: def test_spectral_decrease(self):
      np.testing.assert_almost_equal(spectral_decrease(const0, Fs), 0.0)
      np.testing.assert_almost_equal(spectral_decrease(const1, Fs), 0.0)
      np.testing.assert_almost_equal(
          spectral_decrease(constNeg, Fs), 0.0
      )
      np.testing.assert_almost_equal(spectral_decrease(constF, Fs), 0.0)
      np.testing.assert_almost_equal(
          spectral_decrease(lin, Fs), -2.2331549790804033
      )
      np.testing.assert_almost_equal(
          spectral_decrease(lin0, Fs), 0.49895105698521264, decimal=5
      )
      np.testing.assert_almost_equal(
          spectral_decrease(wave, Fs), 0.19999999999999687, decimal=5
      )
      np.testing.assert_almost_equal(
          spectral_decrease(offsetWave, Fs),
          -26.97129371996163,
          decimal=5,
      )
      np.testing.assert_almost_equal(
          spectral_decrease(noiseWave, Fs),
          0.06049066756953234,
          decimal=5,
      )
  
imports: import unittest
  import numpy
  from tsfel.feature_extraction.features import *
label_desc: Use image node_id 45 for calling the TestFeatures obj's underlying member method code with example usage: obj.test_spectral_decrease() without return types