code: def on_train_batch_begin(self, batch, logs=None):
      self._callback.on_train_batch_begin(batch, logs)
  
imports: import time
  import numpy
  import tensorflow
  from absl import flags
  import keras
label_desc: Use image node_id 2 for calling the TFKerasBenchmarkMetricsCallback obj's underlying member method code with example usage: obj.on_train_batch_begin(batch, logs) without return types