code: def __init__(self, batch_size, epoch_size):
      self.batch_size = batch_size
      self.epoch_size = epoch_size
  
imports: import random
  import nvidia.dali.fn
  import nvidia.dali.ops
  import nvidia.dali.types
  import numpy
  from nvidia.dali import Pipeline, pipeline_def
  from test_utils import check_batch
  from nose_utils import raises, assert_warns, assert_raises
  from nvidia.dali.types import DALIDataType
  from numpy.random import default_rng
label_desc: Use image node_id 1 to create a new SampleCb object  with example: obj = SampleCb(batch_size, epoch_size)