code: def testEmpty(self):
      self.assertEqual(OddToEvenHarmonicEnergyRatio()([], []), 1)
  
file_path: essentia/test/src/unittests/tonal/test_oddtoevenharmonicenergyratio.py
imports: from essentia_test import *
label_desc: Use image node_id 1 for calling the TestOddToEvenHarmonicEnergyRatio obj's underlying member method code with example usage: obj.testEmpty() without return types