code: def __init__(self, start_batch=1, stop_batch=None):
      self.start_batch = start_batch
      self.stop_batch = stop_batch
  
      self.state = {}
  
imports: import time
  import numpy
  import tensorflow
  from absl import flags
  import keras
label_desc: Use image node_id 1 to create a new BenchmarkMetricsCallback object  with example: obj = BenchmarkMetricsCallback(start_batch, stop_batch)