code: def testMp3(self):
      result = MetadataReader(
          filename=join(self.audioDir, "test.mp3")
      )()
      tagsPool = result[7]
      tags = tagsPool.descriptorNames() + [
          tagsPool[t][0] for t in tagsPool.descriptorNames()
      ]
  
      self.assertEqualVector(
          result[:7],
          (
              "test sound",
              "mtg",
              "essentia",
              "this is not reggae",
              "Reggae",
              "01",
              "2009",
          ),
      )
      self.assertEqualVector(result[8:], (5, 128, 44100, 1))
      self.assertEqualVector(
          tags,
          [
              "metadata.tags.album",
              "metadata.tags.artist",
              "metadata.tags.comment",
              "metadata.tags.date",
              "metadata.tags.genre",
              "metadata.tags.title",
              "metadata.tags.tracknumber",
              "essentia",
              "mtg",
              "this is not reggae",
              "2009",
              "Reggae",
              "test sound",
              "01",
          ],
      )
  
file_path: essentia/test/src/unittests/io/test_metadatareader.py
imports: from essentia_test import *
  import os
label_desc: Use image node_id 3 for calling the TestMetadataReader obj's underlying member method code with example usage: obj.testMp3() without return types