code: def node_update(self, nodes):
      return self.node_update_func(nodes)
  
file_path: dgl/examples/pytorch/rrn/rrn.py
imports: import dgl.function
  import torch
  from torch import nn
label_desc: Use image node_id 4 for calling the RRNLayer obj's underlying member method code with example usage: obj.node_update(nodes) and returns: self