code: def testEmpty(self):
      # Test that empty spectrum yields an exception and spectrum of size 1 returns
      # 0 hfc
      self.assertComputeFails(HFC(), [])
  
file_path: essentia/test/src/unittests/spectral/test_hfc.py
imports: from essentia_test import *
  from essentia import *
label_desc: Use image node_id 4 for calling the TestHFC obj's underlying member method code with example usage: obj.testEmpty() without return types