code: def get_one(self):
      idx = self.get_index()
      dir = self.dirs[idx]
  
      imgs = []
      i = 0
      path = os.path.join(dir, "%i.jpg")
      while True:
          fname = path % i
          img = cv2.imread(fname, cv2.IMREAD_GRAYSCALE)
          if img is None:
              break
          i += 1
          imgs.append(img[::-1, :, np.newaxis])
      return np.stack(imgs, axis=0)
  
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 4 for calling the random_3d_loader obj's underlying member method code with example usage: obj.get_one() and returns: np