code: def __init__(self, symbol, model, prefix, rank):
      self.symbol = symbol
      self.model = model
      self.prefix = prefix
      self.max_step = config.max_update
      self.rank = rank
  
imports: import logging
  import os
  import sys
  import time
  import horovod.mxnet
  import mxnet
  from mxboard import SummaryWriter
  from mxnet import nd
  from default import config
  from evaluation import verification
label_desc: Use image node_id 1 to create a new CallBackModelSave object from inherited base classes: object with example: obj = CallBackModelSave(symbol, model, prefix, rank)