code: def testDC(self):
      f0 = 0
      freqs = [0, 110, 220]
      mags = [1, 0, 0]
      hfreqs, hmags = HarmonicPeaks()(freqs, mags, f0)
      self.assertEqualVector(hfreqs, [])
      self.assertEqualVector(hmags, [])
  
      f0 = 20
      freqs = [0, 40, 80]
      mags = [1, 0, 0]
      self.assertComputeFails(HarmonicPeaks(), freqs, mags, f0)
  
file_path: essentia/test/src/unittests/tonal/test_harmonicpeaks.py
imports: from essentia_test import *
label_desc: Use image node_id 9 for calling the TestHarmonicPeaks obj's underlying member method code with example usage: obj.testDC() without return types