docstr: Get datapoint with index
docstr_tok: ["Get","datapoint","with","index"]
code: def __getitem__(self, idx):
      """Get datapoint with index"""
  
      if isinstance(idx, int):
          return self.graphs[idx], self.labels[idx]
      elif torch.is_tensor(idx) and idx.dtype == torch.long:
          if idx.dim() == 0:
              return self.graphs[idx], self.labels[idx]
          elif idx.dim() == 1:
              return Subset(self, idx.cpu())
  
      raise IndexError(
          "Only integers and long are valid "
          "indices (got {}).".format(type(idx).__name__)
      )
  
imports: import os
  import os.path
  import shutil
  from ogb.utils import smiles2graph
  from ogb.utils.torch_util import replace_numpy_with_torchtensor
  from ogb.utils.url import decide_download, download_url, extract_zip
  import pandas
  import numpy
  from dgl.data.utils import load_graphs, save_graphs, Subset
  import dgl
  from tqdm.auto import tqdm
  import torch
label_desc: Use image node_id 5 for calling the DglPCQM4Mv2Dataset obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: self,  self, self,  self, Subset