message: handle StopIteration scenarios for op benchmarking
diff: @@ -52,13 +52,13 @@ class DatasetBenchmarkBase(test.Benchmark):
  """
  if context.executing_eagerly():
  + for _ in range(iters):
  if warmup:
  iterator = iter(op)
  next(iterator)
  iterator = iter(op)
  start = time.time()
  - for _ in range(iters):
  next(iterator)
  end = time.time()
  return (end - start) / iters
  