code: def _get_dataset_obj(self):
      if self._dataset_obj is None:
          self._dataset_obj = dataset.load_dataset(
              data_dir=self._data_dir, **self._dataset_args
          )
      return self._dataset_obj
  
imports: import os
  import time
  import hashlib
  import numpy
  import tensorflow
  import dnnlib
  import dnnlib.tflib
  from training import misc
  from training import dataset
label_desc: Use image node_id 12 for calling the MetricBase obj's underlying member method code with example usage: obj._get_dataset_obj() and returns: self