code: def __init__(self, ctx, axis=None):
      super(ConcatenateDataGrad, self).__init__(ctx)
      self._func = _F.Concatenate(ctx, axis=axis)
  
imports: import nnabla
  import nnabla.function
  import nnabla.functions
  from nnabla.function import PythonFunction
label_desc: Use image node_id 1 to create a new ConcatenateDataGrad object from inherited base classes: PythonFunction with example: obj = ConcatenateDataGrad(ctx, axis)