code: def test_metadata(self):
      data = np.array(1, np.float32, ndmin=3)
      description = "Piano Concerto No. 23 (K488), in **A major.**"
      pb = self.audio("k488", data, 44100, description=description)
      self.assertEqual(len(pb.value), 1)
      summary_metadata = pb.value[0].metadata
      self.assertEqual(
          summary_metadata.summary_description, description
      )
      plugin_data = summary_metadata.plugin_data
      self.assertEqual(plugin_data.plugin_name, metadata.PLUGIN_NAME)
      content = summary_metadata.plugin_data.content
      parsed = metadata.parse_plugin_metadata(content)
      self.assertEqual(parsed.encoding, metadata.Encoding.Value("WAV"))
  
imports: import glob
  import os
  import numpy
  import tensorflow
  from tensorboard.compat import tf2
  from tensorboard.plugins.audio import metadata
  from tensorboard.plugins.audio import summary
  from tensorboard.util import tensor_util
label_desc: Use image node_id 4 for calling the SummaryBaseTest obj's underlying member method code with example usage: obj.test_metadata() without return types