code: def test(loader):
      model.eval()
  
      total_correct = total_examples = 0
      for data in loader:
          data = data.to(device)
          pred = model(data.x, data.edge_index, data.batch).argmax(
              dim=-1
          )
          total_correct += int((pred == data.y).sum())
          total_examples += data.num_graphs
  
      return total_correct / total_examples
  
file_path: pytorch_geometric/examples/upfd.py
imports: import argparse
  import os.path
  import torch
  import torch.nn.functional
  from torch.nn import Linear
  from torch_geometric.datasets import UPFD
  from torch_geometric.loader import DataLoader
  from torch_geometric.nn import GATConv, GCNConv, SAGEConv, global_max_pool
  from torch_geometric.transforms import ToUndirected
label_desc: Use image node_id 2 for calling a global function with example usage: test(loader) and returns: unknown