class_docstr: Base class of pooling function over a set of N-dimensional planes.
class_docstr_tok: ["Base","class","of","pooling","function","over","a","set","of","N-dimensional","planes","."]
code: def backward_cudnn(self, gy):
      assert self._cudnn_pool is not None
      return self._cudnn_pool.backward(gy)
  
file_path: chainer/chainer/functions/pooling/pooling_nd.py
imports: import six
  from chainer.backends import cuda
  from chainer import function_node
  from chainer.utils import conv
  from chainer.utils import conv_nd
  from chainer.utils import type_check
label_desc: Use image node_id 6 for calling the _PoolingND obj's underlying member method code with example usage: obj.backward_cudnn(gy) and returns: self