code: def test_single_input(self):
      input = torch.full(
          (6,),
          dist.get_rank(),
          dtype=torch.half,
          device=get_accelerator().current_device_name(),
      )
  
      (output,) = reduce_scatter_coalesced(
          [input], dist.get_world_group()
      )
  
      assert output.shape == (3,)
      assert torch.allclose(output, torch.full_like(output, 0.5))
  
file_path: deepspeed/tests/unit/runtime/comm/test_coalesced_collectives.py
imports: import torch
  import deepspeed.comm
  from deepspeed.runtime.comm.coalesced_collectives import reduce_scatter_coalesced
  from deepspeed.accelerator import get_accelerator
  from unit.common import DistributedTest
label_desc: Use image node_id 1 for calling the TestReduceScatterCoalesced obj's underlying member method code with example usage: obj.test_single_input() without return types