code: def __init__(self, data_file):
      with open(data_file) as f:
          self.data = [line.strip("\r\n ").split()[0] for line in f]
  
imports: import pickle
  import os
  import random
  import torch
  import numpy
  from torch.utils.data import Dataset, DataLoader
  from .mol_tree import MolTree
  from .jtnn_enc import JTNNEncoder
  from .mpn import MPN
  from .jtmpn import JTMPN
  from .vocab import Vocab
label_desc: Use image node_id 1 to create a new MoleculeDataset object from inherited base classes: Dataset with example: obj = MoleculeDataset(data_file)