docstr: link to download the data 
docstr_tok: ["link","to","download","the","data"]
code: def data_url(self):
      """link to download the data"""
      raise NotImplementedError
  
imports: import os
  import numpy
  import torch.utils.data
  import torchvision.transforms
  import torchvision.datasets
label_desc: Use image node_id 5 for calling the DataProvider obj's underlying member method code with example usage: obj.data_url() without return types