code: def close(self):
      if self._data_file is not None:
          self._data_file.close()
          self._data_file = None
          self._data = None
  
imports: import numpy
  from PIL import Image
  import os
  import io
  import json
  import glob
  import h5py
  from torchmeta.utils.data import Dataset, ClassDataset, CombinationMetaDataset
  from torchmeta.datasets.utils import download_file_from_google_drive
  from torchmeta.datasets.utils import get_asset
label_desc: Use image node_id 7 for calling the CUBClassDataset obj's underlying member method code with example usage: obj.close() without return types