code: def testPCM(self):
      result = MetadataReader(
          filename=join(testdata.audio_dir, "recorded", "musicbox.wav"),
          failOnError=True,
      )()
  
      self.assertTrue(not len(result[7].descriptorNames()))
      self.assertEqualVector(result[:7], ("", "", "", "", "", "", ""))
      self.assertEqualVector(result[8:], (45, 1444, 44100, 2))
  
file_path: essentia/test/src/unittests/io/test_metadatareader.py
imports: from essentia_test import *
  import os
label_desc: Use image node_id 5 for calling the TestMetadataReader obj's underlying member method code with example usage: obj.testPCM() without return types