class_docstr: BaseDataset
class_docstr_tok: ["BaseDataset"]
docstr: getitem
docstr_tok: ["getitem"]
code: def __getitem__(self, idx):
      """getitem"""
      raise NotImplementedError
  
imports: import os
  import sys
  import numpy
  from sklearn.model_selection import StratifiedKFold
  import pgl
  from pgl.utils.logger import log
label_desc: Use image node_id 2 for calling the BaseDataset obj's underlying member method code with example usage: obj.__getitem__(idx) without return types