docstr: Size of dataset image.
docstr_tok: ["Size","of","dataset","image","."]
code: def img_size(self):
      r"""Size of dataset image."""
      if self._dataset_name == "MNIST":
          return 28
      return 32
  
imports: import os
  import pickle
  import numpy
  from scipy.spatial.distance import cdist
  from tqdm import tqdm
  from ..None import backend
  from ..convert import graph
  from .dgl_dataset import DGLDataset
  from .utils import download, extract_archive, load_graphs, save_graphs, Subset
label_desc: Use image node_id 2 for calling the SuperPixelDataset obj's underlying member method code with example usage: obj.img_size() and returns: int, int