class_docstr: Produces [image, label] in Cifar10/100 dataset,
  image is 32x32x3 in the range [0,255].
  label is an int.
code: def __iter__(self):
      idxs = np.arange(len(self.data))
      if self.shuffle:
          self.rng.shuffle(idxs)
      for k in idxs:
          # since cifar is quite small, just do it for safety
          yield self.data[k]
  
imports: import numpy
  import os
  import pickle
  import tarfile
  from ...utils import logger
  from ...utils.fs import download, get_dataset_path
  from ..base import RNGDataFlow
label_desc: Use image node_id 3 for calling the CifarBase obj's underlying member method code with example usage: obj.__iter__() without return types