code: def test():
      model.eval()
      with torch.no_grad():
          z = model(x, train_pos_edge_index, train_neg_edge_index)
      return model.test(z, test_pos_edge_index, test_neg_edge_index)
  
imports: import os.path
  import torch
  from torch_geometric.datasets import BitcoinOTC
  from torch_geometric.nn import SignedGCN
label_desc: Use image node_id 2 for calling a global function with example usage: test() and returns: model