code: def __len__(self):
      return len(self.y)
  
imports: import logging
  import os
  import random
  import time
  import urllib.request
  from typing import Optional, Sequence, Tuple
  import torch
  from torch import Tensor
  from torch.utils.data import Dataset
label_desc: Use image node_id 3 for calling the SklearnDataset obj's underlying member method code with example usage: obj.__len__() and returns: len