code: def forward(self, x_dict, edge_index_dict, edge_label_index):
      z_dict = self.encoder(x_dict, edge_index_dict)
      return self.decoder(z_dict, edge_label_index)
  
file_path: pytorch_geometric/examples/explain/captum_explainer_hetero_link.py
imports: import os.path
  import torch
  import torch.nn.functional
  from torch.nn import Linear
  import torch_geometric.transforms
  from torch_geometric.datasets import MovieLens
  from torch_geometric.explain import CaptumExplainer, Explainer
  from torch_geometric.nn import SAGEConv, to_hetero
label_desc: Use image node_id 2 for calling the Model obj's underlying member method code with example usage: obj.forward(x_dict, edge_index_dict, edge_label_index) and returns: self