code: def check_forward(self, x):
      self.f.apply((chainer.Variable(x),))
      self.assertEqual(1, len(self.h.call_history))
      check_history(
          self,
          self.h.call_history[0],
          functions.math.exponential.Exp,
          int,
          int,
      )
  
imports: 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 3 for calling the TestCupyMemoryProfileHookToFunction obj's underlying member method code with example usage: obj.check_forward(x) without return types