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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def parse_plugin_metadata(content):
 """Parse summary metadata to a Python object. Arguments: content: The `content` field of a `SummaryMetadata` proto corresponding to the pr_curves plugin. Returns: A `PrCurvesPlugin` protobuf object. """

  if not isinstance(content, bytes):
    raise TypeError('Content type must be bytes')
  result = plugin_data_pb2.PrCurvePluginData.FromString(content)
  if result.version == 0:
    return result
  else:
    logger.warn(
        'Unknown metadata version: %s. The latest version known to '
        'this build of TensorBoard is %s; perhaps a newer build is '
        'available?', result.version, PROTO_VERSION)
    return result