code: def begin(self):
      if self.model_dir is not None:
          self.summary_writer = (
              tf.compat.v1.summary.FileWriterCache.get(self.model_dir)
          )
          self.global_step_tensor = (
              tf.compat.v1.train.get_or_create_global_step()
          )
      else:
          self.step = 0
  
imports: import itertools
  import numpy
  import tensorflow
  from tensorflow_estimator.python.estimator.export.export import build_supervised_input_receiver_fn_from_input_fn
label_desc: Use image node_id 2 for calling the _TrainLogHook obj's underlying member method code with example usage: obj.begin() without return types