class_docstr: CORe50 Pytorch Dataset
class_docstr_tok: ["CORe50","Pytorch","Dataset"]
code: def _download_error_message(self) -> str:
      all_urls = [name_url[1] for name_url in core50_data.data]
  
      base_msg = (
          "[CORe50] Error downloading the dataset!\n"
          "You should download data manually using the following links:\n"
      )
  
      for url in all_urls:
          base_msg += url
          base_msg += "\n"
  
      base_msg += "and place these files in " + str(self.root)
  
      return base_msg
  
imports: import glob
  import os
  import pickle
  from pathlib import Path
  from typing import List, Optional, Tuple, Union
  from warnings import warn
  from torchvision.datasets.folder import default_loader
  from torchvision.transforms import ToTensor
  from avalanche.benchmarks.datasets.core50 import core50_data
  from avalanche.benchmarks.datasets import default_dataset_location
  from avalanche.benchmarks.datasets.downloadable_dataset import DownloadableDataset
label_desc: Use image node_id 6 for calling the CORe50Dataset obj's underlying member method code with example usage: obj._download_error_message() and returns: base_msg