docstr: At least 3 reserved keys should be fiiled: 'vocab', 'data' and 'split_ids'.
docstr_tok: ["At","least","3","reserved","keys","should","be","fiiled",":","'vocab","'",",","'data","'","and","'split_ids","'","."]
code: def processed_file_names(self):
      """At least 3 reserved keys should be fiiled: 'vocab', 'data' and 'split_ids'."""
      return {"vocab": "vocab.pt", "data": "data.pt"}
  
file_path: graph4nlp/examples/pytorch/nmt/dataset.py
imports: import pickle
  import nltk
  import torch
  from graph4nlp.pytorch.data.dataset import Text2TextDataItem, Text2TextDataset
  from graph4nlp.pytorch.modules.utils.padding_utils import pad_2d_vals_no_size
label_desc: Use image node_id 2 for calling the IWSLT14Dataset obj's underlying member method code with example usage: obj.processed_file_names() and returns: dict