code: def num_examples(self):
      return self.labels.shape[0]
  
imports: import tempfile
  import os
  import pickle
  import random
  import numpy
  from data_providers.base_provider import ImagesDataSet, DataProvider
  from data_providers.downloader import download_data_url
label_desc: Use image node_id 3 for calling the CifarDataSet obj's underlying member method code with example usage: obj.num_examples() and returns: self