code: def millis(self):
      return self.start_.elapsed_time(self.stop_)
  
file_path: apex/apex/contrib/test/layer_norm/test_fast_layer_norm.py
imports: import itertools
  import unittest
  import torch
label_desc: Use image node_id 5 for calling the GPUTimer obj's underlying member method code with example usage: obj.millis() and returns: self