code: def check_backward(self, x_data, y_grad):
      def f(x):
          x_min, x_max = self.x_min_max
          return functions.clip(x, x_min, x_max)
  
      gradient_check.check_backward(
          f, x_data, y_grad, dtype=numpy.float64
      )
  
imports: import unittest
  import numpy
  import chainer
  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 5 for calling the TestClip obj's underlying member method code with example usage: obj.check_backward(x_data, y_grad) and returns: functions