code: def ref_reduce_scatter(x_data_list, size, division):
      f = reduce(lambda x, y: x + y, np.arange(size)) + size
      results = []
      for x_data in x_data_list:
          result = x_data * f
          if division:
              result /= size
          results.append(result)
      return results
  
file_path: nnabla/python/test/communicator/test_reduce_scatter.py
imports: import pytest
  import nnabla
  import nnabla.parametric_functions
  import numpy
  from nnabla.testing import assert_allclose
  from six.moves import reduce
label_desc: Use image node_id 1 for calling a global function with example usage: ref_reduce_scatter(x_data_list, size, division) and returns: results