code: def build_hidden_layer(self, idx):
      raise NotImplementedError
  
file_path: dgl/benchmarks/benchmarks/multigpu/rgcn_model.py
imports: import dgl
  import torch
  import torch.nn
label_desc: Use image node_id 4 for calling the BaseRGCN obj's underlying member method code with example usage: obj.build_hidden_layer(idx) without return types