code: def normalize(self, x):
      return (x - self.mean) / self.std
  
file_path: dgl/examples/pytorch/dtgrnn/utils.py
imports: import dgl
  import numpy
  import scipy.sparse
  import torch
  import torch.nn
label_desc: Use image node_id 2 for calling the NormalizationLayer obj's underlying member method code with example usage: obj.normalize(x) and returns: unknown