code: def testEmpty(self):
      # Checks whether an empty input vector yields an exception
      self.assertComputeFails(Chromagram(), [])
  
file_path: essentia/test/src/unittests/standard/test_chromagram.py
imports: from essentia_test import *
  import math
  import numpy
  import os
label_desc: Use image node_id 4 for calling the TestChromagram obj's underlying member method code with example usage: obj.testEmpty() without return types