docs: def _send_picklemetrics(metrics):
      '''
      Format metrics for the carbon pickle protocol
      '''
  
      metrics = [(metric_name, (timestamp, value))
                 for (metric_name, value, timestamp) in metrics]
  
      data = cPickle.dumps(metrics, -1)
      payload = struct.pack(b'!L', len(data)) + data
  
      return payload