code: def _wrap_callback_parse_parameter_data(subscription, on_data, message):
      
      if message.type == message.REPLY:
          data = web_pb2.ParameterSubscriptionResponse()
          data.ParseFromString(message.reply.data)
          subscription.subscription_id = data.subscriptionId
      elif (message.type == message.DATA and
            message.data.type == yamcs_pb2.PARAMETER):
          parameter_data = ParameterData(getattr(message.data, 'parameterData'))
          #pylint: disable=protected-access
          subscription._process(parameter_data)
          if on_data:
              on_data(parameter_data)
docs: Wraps an (optional) user callback to parse ParameterData
      from a WebSocket data message