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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 _pickle_batch(self):
 """ Pickle the metrics into a form that can be understood by the graphite pickle connector. """

        # Pickle
        payload = pickle.dumps(self.batch)

        # Pack Message
        header = struct.pack("!L", len(payload))
        message = header + payload

        # Return Message
        return message