code: def lower_upper(self):
      if self._lower_upper is None:
          with open(self.split_filename_lower_upper, "r") as f:
              self._lower_upper = json.load(f)
      return self._lower_upper["lower"], self._lower_upper["upper"]
  
imports: import numpy
  import os
  import json
  import h5py
  from tqdm import tqdm
  from torchmeta.utils.data import Dataset, ClassDataset, CombinationMetaDataset
  from torchmeta.datasets.utils import get_asset
label_desc: Use image node_id 6 for calling the PlantsMarginClassDataset obj's underlying member method code with example usage: obj.lower_upper() and returns: self,  self