class_docstr: Base Dataset with directory checker.
  
  Parameters
  ----------
  root : str
      The root path of xxx.names, by default is '~/.mxnet/datasets/foo', where
      `foo` is the name of the dataset.
class_docstr_tok: ["Base","Dataset","with","directory","checker",".","Parameters","--","--","--","--","--","root",":","str","The","root","path","of","xxx.names",",","by","default","is","'~\/.mxnet\/datasets\/foo","'",",","where","`","foo","`","is","the","name","of","the","dataset","."]
code: def classes(self):
      raise NotImplementedError
  
file_path: gluon-cv/gluoncv/data/base.py
imports: import os
  from mxnet.gluon.data import dataset
label_desc: Use image node_id 2 for calling the VisionDataset obj's underlying member method code with example usage: obj.classes() without return types