code: def forward(self, batch):
      x, edge_index, x_batch = (
          batch.node_feature,
          batch.edge_index,
          batch.batch,
      )
  
      for i in range(len(self.convs)):
          x = self.convs[i](x, edge_index)
          x = F.relu(x)
          x = F.dropout(x, p=self.dropout, training=self.training)
  
      x = pyg_nn.global_add_pool(x, x_batch)
      x = self.post_mp(x)
      x = F.log_softmax(x, dim=1)
      batch.node_feature = x
      return batch
  
file_path: GraphGym/graphgym/contrib/network/example.py
imports: import torch
  import torch.nn
  import torch.nn.functional
  import torch_geometric.nn
  from torch_geometric.graphgym.models import MLP
  from graphgym.config import cfg
  from graphgym.register import register_network
label_desc: Use image node_id 3 for calling the ExampleGNN obj's underlying member method code with example usage: obj.forward(batch) and returns: batch