code: def test_negative_turning(self):
      np.testing.assert_almost_equal(negative_turning(const0), 0.0)
      np.testing.assert_almost_equal(negative_turning(const1), 0.0)
      np.testing.assert_almost_equal(negative_turning(constNeg), 0.0)
      np.testing.assert_almost_equal(negative_turning(constF), 0.0)
      np.testing.assert_almost_equal(negative_turning(lin), 0.0)
      np.testing.assert_almost_equal(
          negative_turning(lin0), 0.0, decimal=5
      )
      np.testing.assert_almost_equal(
          negative_turning(wave), 5, decimal=5
      )
      np.testing.assert_almost_equal(
          negative_turning(offsetWave), 5, decimal=5
      )
      np.testing.assert_almost_equal(
          negative_turning(noiseWave), 323, decimal=5
      )
  
imports: import unittest
  import numpy
  from tsfel.feature_extraction.features import *
label_desc: Use image node_id 19 for calling the TestFeatures obj's underlying member method code with example usage: obj.test_negative_turning() without return types