code: def __init__(self, in_size, out_size, hidden_size=16):
      super().__init__()
  
      # Two-layer GCN.
      self.W1 = nn.Linear(in_size, hidden_size)
      self.W2 = nn.Linear(hidden_size, out_size)
  
file_path: dgl/examples/sparse/gcn.py
imports: import dgl.sparse
  import torch
  import torch.nn
  import torch.nn.functional
  from dgl.data import CoraGraphDataset
  from torch.optim import Adam
label_desc: Use image node_id 1 to create a new GCN object from inherited base classes: nn with example: obj = GCN(in_size, out_size, hidden_size)