code: def testEmpty(self):
      gen = VectorInput([])
      beatsLoudness = BeatsLoudness()
      p = Pool()
  
      gen.data >> beatsLoudness.signal
      beatsLoudness.loudness >> (p, "beats.loudness")
      beatsLoudness.loudnessBandRatio >> (p, "beats.loudnessBandRatio")
  
      run(gen)
  
      self.assertEqual(len(p.descriptorNames()), 0)
  
file_path: essentia/test/src/unittests/rhythm/test_beatsloudness_streaming.py
imports: from essentia_test import *
  from essentia.streaming import BeatsLoudness, MonoLoader, RhythmExtractor
label_desc: Use image node_id 2 for calling the TestBeatsLoudness obj's underlying member method code with example usage: obj.testEmpty() without return types