code: def __init__(self, input_size, output_size, num_layers=3):
      super(GNNModel, self).__init__()
      self.conv_fn = nn.LayerList()
      self.conv_fn.append(gnn.GCNConv(input_size, output_size))
      for i in range(num_layers - 1):
          self.conv_fn.append(gnn.GCNConv(output_size, output_size))
      self.pool_fn = gnn.GraphPool("sum")
  
file_path: PGL/examples/deploy_gnn/train.py
imports: import paddle
  import pgl
  import paddle.nn
  import pgl.nn
  from ogb.utils import smiles2graph
label_desc: Use image node_id 1 to create a new GNNModel object from inherited base classes: nn with example: obj = GNNModel(input_size, output_size, num_layers)