class_docstr: Cross-channel normalization function used in AlexNet.
code: def backward(self, indexes, grad_outputs):
      (x,) = self.get_retained_inputs()
      (y,) = self.get_retained_outputs()
      (gy,) = grad_outputs
  
      f = LocalResponseNormalizationGrad(
          self.n,
          self.k,
          self.alpha,
          self.beta,
          self._use_ideep,
          self.scale,
          self.indexes,
          self.unit_scale,
      )
      return f.apply((x, y, gy))
  
imports: import numpy
  import six
  from chainer.backends import cuda
  from chainer.backends import intel64
  from chainer import function_node
  from chainer.utils import type_check
label_desc: Use image node_id 6 for calling the LocalResponseNormalization obj's underlying member method code with example usage: obj.backward(indexes, grad_outputs) and returns: f