code: def test_metadata(self):
      data = np.array(1, np.uint8, ndmin=4)
      description = "By Leonardo da Vinci"
      pb = self.image("mona_lisa", data, description=description)
      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
      # There's no content, so successfully parsing is fine.
      metadata.parse_plugin_metadata(content)
  
imports: import glob
  import os
  import numpy
  import tensorflow
  from tensorboard.compat import tf2
  from tensorboard.compat.proto import summary_pb2
  from tensorboard.plugins.image import metadata
  from tensorboard.plugins.image import summary
label_desc: Use image node_id 5 for calling the SummaryBaseTest obj's underlying member method code with example usage: obj.test_metadata() without return types