class_docstr: Average pooling over a set of N-dimensional planes.
  
  .. warning::
  
      This feature is experimental. The interface can change in the future.
code: def backward(self, indexes, gy):
      return AveragePoolingNDGrad(self).apply(gy)
  
imports: import functools
  import operator
  import numpy
  import six
  import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import function_node
  from chainer.functions.pooling import average_pooling_nd_kernel
  from chainer.functions.pooling import pooling_nd
  from chainer.utils import conv
  from chainer.utils import conv_nd
  import chainerx
label_desc: Use image node_id 6 for calling the AveragePoolingND obj's underlying member method code with example usage: obj.backward(indexes, gy) and returns: AveragePoolingNDGrad