code: def check_forward(self, h_data, x_data):
      h = chainer.Variable(h_data)
      x = chainer.Variable(x_data)
      h_next = functions.zoneout(h, x, self.ratio)
      if self.ratio == 0:
          h_next_expect = x_data
      elif self.ratio == 1:
          h_next_expect = h_data
      else:
          h_next_expect = _zoneout(h_data, x_data, h_next.creator)
      testing.assert_allclose(h_next.data, h_next_expect)
  
imports: import unittest
  import mock
  import numpy
  import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 2 for calling the TestZoneout obj's underlying member method code with example usage: obj.check_forward(h_data, x_data) without return types