code: def chordHelper(self, half_steps, tunning, strength):
      notes = [
          tunning * (2.0 ** (half_steps[i] / 12.0))
          for i in range(len(half_steps))
      ]
      hpcp = HPCP(maxShifted=False)(
          [notes[0], notes[1], notes[2]], strength
      )
      for i in range(len(hpcp)):
          if i in half_steps:
              self.assertTrue(hpcp[i] > 0)
          elif (i - 12) in half_steps:
              self.assertTrue(hpcp[i] > 0)
          else:
              self.assertEqual(hpcp[i], 0)
  
file_path: essentia/test/src/unittests/spectral/test_hpcp.py
imports: from essentia_test import *
label_desc: Use image node_id 7 for calling the TestHPCP obj's underlying member method code with example usage: obj.chordHelper(half_steps, tunning, strength) without return types