code: def forward(self, batch):
      x, edge_index = batch.x, batch.edge_index
  
      for i in range(len(self.convs)):
          x = self.convs[i](x, edge_index)
          x = F.relu(x)
          x = F.dropout(x, p=0.1, training=self.training)
  
      batch.x = x
      batch = self.post_mp(batch)
  
      return batch
  
file_path: pytorch_geometric/graphgym/custom_graphgym/network/example.py
imports: import torch
  import torch.nn
  import torch.nn.functional
  import torch_geometric.graphgym.models.head
  import torch_geometric.graphgym.register
  import torch_geometric.nn
  from torch_geometric.graphgym.config import cfg
  from torch_geometric.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