code: def __init__(self, ctx, kernel, channel_last=False):
      super(UnpoolingDataGrad, self).__init__(ctx)
      self._func = _F.Unpooling(ctx, kernel, channel_last)
  
file_path: nnabla/python/src/nnabla/backward_function/unpooling.py
imports: import nnabla
  import nnabla.function
  import nnabla.functions
  from .backward_function import UnaryDataGrad
label_desc: Use image node_id 1 to create a new UnpoolingDataGrad object from inherited base classes: UnaryDataGrad with example: obj = UnpoolingDataGrad(ctx, kernel, channel_last)