code: def encode(self, x, edge_index):
      x = self.conv1(x, edge_index).relu()
      return self.conv2(x, edge_index)
  
file_path: pytorch_geometric/examples/link_pred.py
imports: import os.path
  import torch
  from sklearn.metrics import roc_auc_score
  import torch_geometric.transforms
  from torch_geometric.datasets import Planetoid
  from torch_geometric.nn import GCNConv
  from torch_geometric.utils import negative_sampling
label_desc: Use image node_id 2 for calling the Net obj's underlying member method code with example usage: obj.encode(x, edge_index) and returns: self