code: def testOne(self):
      self.assertEqual(HFC()([9]), 0)
  
file_path: essentia/test/src/unittests/spectral/test_hfc.py
imports: from essentia_test import *
  from essentia import *
label_desc: Use image node_id 5 for calling the TestHFC obj's underlying member method code with example usage: obj.testOne() without return types