Retrieve a particular plugin asset from a logdir.

  Args:
    logdir: A directory that was created by a TensorFlow summary.FileWriter.
    plugin_name: The plugin we want an asset from.
    asset_name: The name of the requested asset.

  Returns:
    string contents of the plugin asset.

  Raises:
    KeyError: if the asset does not exist.

def RetrieveAsset(logdir, plugin_name, asset_name):
  """Retrieve a particular plugin asset from a logdir.

  Args:
    logdir: A directory that was created by a TensorFlow summary.FileWriter.
    plugin_name: The plugin we want an asset from.
    asset_name: The name of the requested asset.

  Returns:
    string contents of the plugin asset.

  Raises:
    KeyError: if the asset does not exist.
  """

  asset_path = os.path.join(PluginDirectory(logdir, plugin_name), asset_name)
  try:
    with tf.io.gfile.GFile(asset_path, "r") as f:
      return f.read()
  except tf.errors.NotFoundError:
    raise KeyError("Asset path %s not found" % asset_path)
  except tf.errors.OpError as e:
    raise KeyError("Couldn't read asset path: %s, OpError %s" % (asset_path, e))