code: def __getitem__(self, idx):
      (
          exclude_graph_X,
          exclude_graph_edge_index,
      ) = self.subgraph_build_func(
          self.X, self.edge_index, self.exclude_mask[idx]
      )
      (
          include_graph_X,
          include_graph_edge_index,
      ) = self.subgraph_build_func(
          self.X, self.edge_index, self.include_mask[idx]
      )
      exclude_data = Data(
          x=exclude_graph_X, edge_index=exclude_graph_edge_index
      )
      include_data = Data(
          x=include_graph_X, edge_index=include_graph_edge_index
      )
      return exclude_data, include_data
  
imports: import copy
  import torch
  import numpy
  from scipy.special import comb
  from itertools import combinations
  import torch.nn.functional
  from torch_geometric.utils import to_networkx
  from torch_geometric.data import Data, Batch, Dataset
  from torch_geometric.loader import DataLoader
label_desc: Use image node_id 3 for calling the MarginalSubgraphDataset obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: exclude_data,  include_data