code: def forward_expected(self, inputs):
      a, b = inputs
      a_copy = a.copy()
      numpy.add.at(a_copy, self.slices, b)
      return (a_copy,)
  
file_path: chainer/tests/chainer_tests/functions_tests/array_tests/test_scatter_add.py
imports: import unittest
  import numpy
  import chainer
  from chainer import functions
  from chainer import testing
  from chainer.utils import type_check
label_desc: Use image node_id 4 for calling the TestScatterAdd obj's underlying member method code with example usage: obj.forward_expected(inputs) and returns: a_copy