code: def testHarmonics(self):
      # Regression test for the 'harmonics' parameter
      tone = 100.0  # arbitrary frequency [Hz]
      freqs = [tone, tone * 2, tone * 3, tone * 4]
      mags = [1] * 4
  
      hpcpAlg = HPCP(
          minFrequency=50,
          maxFrequency=500,
          bandPreset=False,
          harmonics=3,
      )
      hpcp = hpcpAlg(freqs, mags)
      expected = [
          0.0,
          0.0,
          0.0,
          0.1340538263,
          0.0,
          0.2476127148,
          0.0,
          0.0,
          0.0,
          0.0,
          1.0,
          0.0,
      ]
      self.assertAlmostEqualVector(hpcp, expected, 1e-4)
  
file_path: essentia/test/src/unittests/spectral/test_hpcp.py
imports: from essentia_test import *
label_desc: Use image node_id 15 for calling the TestHPCP obj's underlying member method code with example usage: obj.testHarmonics() without return types