code: def forward(self, inputs):
      slices = tuple(
          [
              backend.from_chx(s)
              if isinstance(s, chainerx.ndarray)
              else s
              for s in self.slices
          ]
      )
  
      (gy,) = inputs
      xp = backend.get_array_module(*inputs)
      gx = xp.zeros(self._in_shape, gy.dtype)
      if xp is numpy:
          try:
              numpy.add.at(gx, slices, gy)
          except IndexError:
              done = False
              # In numpy<1.13, 0-dim boolean index is not supported in
              # numpy.add.at and it's supported for 0-dim arr in
              # arr.__getitem__.
              if not _numpy_supports_0d_bool_index and len(slices) == 1:
                  idx = numpy.asanyarray(slices[0])
                  if idx.dtype == numpy.dtype(bool):
                      # Convert the array and the mask to 1-dim.
                      # numpy.add.at with them is supported in older numpy.
                      numpy.add.at(gx[None], idx[None], gy)
                      done = True
  
              if not done:
                  msg = """
  GetItem does not support backward for this slices. The slices argument is not
  supported by numpy.add.at, while it is supported by numpy.ndarray.__getitem__.
  
  Please report this error to the issue tracker with the stack trace,
  the information of your environment, and your script:
  https://github.com/chainer/chainer/issues/new.
  """
                  raise IndexError(msg)
      else:
          gx.scatter_add(slices, inputs[0])
      return (gx,)
  
imports: import numpy
  import chainer
  from chainer import backend
  from chainer import function_node
  from chainer import utils
  from chainer.utils import type_check
  from chainer import variable
  import chainerx
label_desc: Use image node_id 2 for calling the GetItemGrad obj's underlying member method code with example usage: obj.forward(inputs) and returns: gx