code: def __getitem__(self, i):
      return {
          "text": self.dataset[i][self.key1],
          "text_pair": self.dataset[i][self.key2],
      }
  
imports: import numpy
  import torch
  from torch.utils.data import Dataset, IterableDataset
label_desc: Use image node_id 3 for calling the KeyPairDataset obj's underlying member method code with example usage: obj.__getitem__(i) and returns: dict