code: def on_epoch_begin(self, epoch, logs=None):
      print(
          "epoch {} batch {}".format(self.state.epoch, self.state.batch)
      )
  
file_path: horovod/test/integration/data/elastic_tensorflow_keras_main.py
imports: import argparse
  import json
  import os
  import psutil
  import time
  import tensorflow
  import horovod.tensorflow.keras
label_desc: Use image node_id 3 for calling the TestCallback obj's underlying member method code with example usage: obj.on_epoch_begin(epoch, logs) without return types