code: def test_reentrant_total_time(self):
      g = functions.math.identity.Identity()
  
      t0 = _get_time()
      self.h.backward_preprocess(self.f, (self.x,), (self.gy,))
      t1 = _get_time()
      self.h.forward_preprocess(g, (self.x,))
      time.sleep(0.001)
      self.h.forward_postprocess(g, (self.x,))
      t2 = _get_time()
      self.h.backward_postprocess(self.f, (self.x,), (self.gy,))
      t3 = _get_time()
  
      assert self.h.total_time() <= t3 - t0
      assert self.h.total_time() >= t2 - t1
  
imports: import os
  import time
  import unittest
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
  from chainer import function_hooks
  from chainer import functions
  from chainer.functions.math import basic_math
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 9 for calling the TestTimerHookToFunction obj's underlying member method code with example usage: obj.test_reentrant_total_time() without return types