code: def check_backward_no_reduction(self, x_data, t_data, y_grad):
      # Skip too large case. That requires a long time.
      if self.shape[0] == 65536:
          return
  
      def f(x, t):
          return chainer.functions.sigmoid_cross_entropy(
              x, t, reduce="no"
          )
  
      gradient_check.check_backward(
          f, (x_data, t_data), y_grad, **self.check_backward_options
      )
  
imports: import math
  import unittest
  import numpy
  import six
  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
  from chainer import utils
label_desc: Use image node_id 11 for calling the TestSigmoidCrossEntropy obj's underlying member method code with example usage: obj.check_backward_no_reduction(x_data, t_data, y_grad) and returns: chainer