class_docstr: The StanfordCars dataset, mapping images to their respective class
code: def _open_annotations(self):
      annotations = None
      if self.split == "train":
          annotations = io.loadmat(
              os.path.join(self.root, "devkit/cars_train_annos.mat")
          )
      elif self.split == "test":
          annotations = io.loadmat(
              os.path.join(self.root, "cars_test_annos_withlabels.mat")
          )
      return annotations["annotations"][0]
  
imports: import argparse
  import os
  import shutil
  from scipy import io
  from torch.utils.data import DataLoader
  from tqdm import tqdm
  from vissl.utils.download import download_and_extract_archive, download_url
  from vissl.utils.io import cleanup_dir
label_desc: Use image node_id 2 for calling the StanfordCars obj's underlying member method code with example usage: obj._open_annotations() and returns: annotations