code: def init_variables(self):
      self.session.run(self.init_op)
  
imports: import math
  import random
  import sys
  import numpy
  import tensorflow
  from .sentence_grouper import SentenceGrouper
  from ..tf2contrib import *
label_desc: Use image node_id 20 for calling the NerModel obj's underlying member method code with example usage: obj.init_variables() without return types