code: def process(self) -> None:
      num_nodes = self.num_clusters * 3
      chunk_size = num_nodes + 2
      z, pos = read_atoms(self.raw_paths[0], chunk_size)
      y = read_energy(self.raw_paths[0], chunk_size)
      np.savez(
          self.processed_paths[0],
          z=z,
          pos=pos,
          y=y,
          num_graphs=z.shape[0],
      )
  
imports: import copy
  import os
  import os.path
  from dataclasses import dataclass
  from functools import cached_property
  from glob import glob
  from pathlib import Path
  from typing import Callable, List, MutableSequence, Optional, Tuple, Union
  import numpy
  import torch
  from torch.utils.data import ConcatDataset, Subset
  from torch_geometric.data import Data, InMemoryDataset, download_url, extract_zip
  from torch_geometric.data.data import BaseData
label_desc: Use image node_id 4 for calling the Partition obj's underlying member method code with example usage: obj.process() without return types