code: def __len__(self) -> int:
      return len(self.dataset)
  
imports: import copy
  from typing import Any, Callable, Iterator, Optional, Sequence
  import torch
  from torch_geometric.data import Batch
  from torch_geometric.utils import from_smiles
label_desc: Use image node_id 5 for calling the DatasetAdapter obj's underlying member method code with example usage: obj.__len__() and returns: len