code: def __init__(self, batch_size):
      np.random.seed(12345)
      self.subdirs = [
          "SER00004",
          "SER00006",
          "SER00008",
          "SER00009",
          "SER00011",
          "SER00015",
      ]
      self.dirs = [os.path.join(db_3d_folder, x) for x in self.subdirs]
      self.batch_size = batch_size
      np.random.seed(1234)
      self.n = 0
      self.order = list(range(len(self.subdirs)))
      np.random.shuffle(self.order)
  
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 1 to create a new random_3d_loader object  with example: obj = random_3d_loader(batch_size)