code: def __iter__(self):
      return self
  
imports: import cv2
  import functools
  import math
  import numpy
  import nvidia.dali
  import nvidia.dali.fn
  import nvidia.dali.types
  import os.path
  from nvidia.dali import Pipeline, pipeline_def
  from nvidia.dali.data_node import DataNode
  from test_utils import check_batch, get_dali_extra_path, as_array
  import PIL.Image
label_desc: Use image node_id 2 for calling the random_3d_loader obj's underlying member method code with example usage: obj.__iter__() and returns: self