code: def test_elapsed_time(self):
      with self.assertRaises(RuntimeError):
          self.trainer.elapsed_time
  
      self.trainer.run()
  
      self.assertGreater(self.trainer.elapsed_time, 0)
  
imports: import time
  import traceback
  import unittest
  from chainer import testing
  from chainer import training
label_desc: Use image node_id 3 for calling the TestTrainer obj's underlying member method code with example usage: obj.test_elapsed_time() without return types