class_docstr: base class for classfication 
code: def get_scaffold(self, mode, global_step=None):
      if mode != utils.TRAIN:
          # for model average
          saver = self.get_saver(global_step)
          scaffold = tf.train.Scaffold(saver=saver)
      else:
          scaffold = None  # default
      return scaffold
  
imports: import os
  import re
  import functools
  import collections
  from absl import logging
  import delta.compat
  from tensorflow.python import debug
  from tensorflow.python.estimator.canned import metric_keys
  from tensorboard.plugins.pr_curve import summary
  from delta import utils
  from delta.utils.hparam import HParams
  from delta.utils import metrics
  from delta.utils import summary
  from delta.utils.register import registers
  from delta.utils.solver.base_solver import ABCEstimatorSolver
label_desc: Use image node_id 3 for calling the EstimatorSolver obj's underlying member method code with example usage: obj.get_scaffold(mode, global_step) and returns: scaffold