class_docstr: Base class for downloading sample datasets.
  
  This class is used by inherited classes for each specific dataset, providing basic functionality to
  download a dataset from a URL.
  
  The default download path of ~/stellargraph-datasets can be changed by setting the STELLARGRAPH_DATASETS_PATH environment variable,
  and each dataset will be downloaded to a subdirectory within this path.
class_docstr_tok: ["Base","class","for","downloading","sample","datasets",".","This","class","is","used","by","inherited","classes","for","each","specific","dataset",",","providing","basic","functionality","to","download","a","dataset","from","a","URL",".","The","default","download","path","of","~\/stellargraph-datasets","can","be","changed","by","setting","the","STELLARGRAPH_DATASETS_PATH","environment","variable",",","and","each","dataset","will","be","downloaded","to","a","subdirectory","within","this","path","."]
docstr: Returns true if the expected files for the dataset are present
docstr_tok: ["Returns","true","if","the","expected","files","for","the","dataset","are","present"]
code: def _is_downloaded(self) -> bool:
      """Returns true if the expected files for the dataset are present"""
      return len(self._missing_files()) == 0
  
file_path: stellargraph/stellargraph/datasets/dataset_loader.py
imports: import os
  import logging
  from shutil import unpack_archive, move
  from urllib.request import urlretrieve
  from typing import List, Optional, Any
  from urllib.error import URLError
label_desc: Use image node_id 10 for calling the DatasetLoader obj's underlying member method code with example usage: obj._is_downloaded() and returns: unknown