code: def __init__(self, pred_idx=-1, label_idx=-1):
      super(RPNLogLossMetric, self).__init__("RPNLogLoss")
      self.pred, self.label = get_rpn_names()
      self.pred_idx = pred_idx
      self.label_idx = label_idx
  
imports: from __future__ import print_function
  import sys
  import mxnet
  import numpy
  from rcnn.config import config
label_desc: Use image node_id 1 to create a new RPNLogLossMetric object from inherited base classes: mx.metric with example: obj = RPNLogLossMetric(pred_idx, label_idx)