code: def __init__(self, hidden_size):
      nn.Module.__init__(self)
      self.hidden_size = hidden_size
  
      self.W = nn.Linear(2 * hidden_size, hidden_size)
  
file_path: dgl/examples/pytorch/jtnn/jtnn/jtnn_enc.py
imports: import dgl.function
  import numpy
  import torch
  import torch.nn
  from dgl import batch, bfs_edges_generator, line_graph
  from .nnutils import cuda, GRUUpdate, tocpu
label_desc: Use image node_id 1 to create a new EncoderGatherUpdate object from inherited base classes: nn with example: obj = EncoderGatherUpdate(hidden_size)