code: def forward(self, x, edge_index):
      x = torch.nn.functional.relu(self.conv1(x, edge_index))
      x = self.conv2(x, edge_index)
      return x
  
file_path: pytorch_geometric/test/visualization/test_influence.py
imports: import torch
  from torch_geometric.datasets import KarateClub
  from torch_geometric.nn import GCNConv
  from torch_geometric.visualization import influence
label_desc: Use image node_id 2 for calling the Net obj's underlying member method code with example usage: obj.forward(x, edge_index) and returns: x