code: def test_reduce_scatter(self):
      to_reduce_scatter = [
          torch.ones(3, 3) * rank for rank in range(self.world_size)
      ]
      output_tensor = torch.empty(3, 3)
  
      dist.reduce_scatter(output_tensor, to_reduce_scatter)
      expected_tensor = (
          torch.ones(3, 3) * dist.get_rank() * self.world_size
      )
      self.assertEqual(output_tensor, expected_tensor)
  
imports: import os
  import sys
  import torch
  import torch.distributed
  from torch._C._distributed_c10d import ReduceOp
  from unittest import skip, SkipTest
  import operator
  from functools import reduce
  import threading
  import torch.autograd
  from torch.testing._internal.common_distributed import spawn_threads_and_init_comms, MultiThreadedTestCase, skip_if_lt_x_gpu
  from torch.testing._internal.common_utils import TestCase, run_tests, IS_SANDCASTLE
label_desc: Use image node_id 7 for calling the TestCollectivesWithBaseClass obj's underlying member method code with example usage: obj.test_reduce_scatter() without return types