code: def forward(ctx, input_, dim, parallel_mode):
      ctx.dim = dim
      ctx.parallel_mode = parallel_mode
      return reduce_scatter(input_, dim, parallel_mode)
  
imports: from typing import Any, Tuple
  import torch
  import torch.distributed
  from torch import Tensor
  from torch.cuda.amp import custom_bwd, custom_fwd
  from colossalai.legacy.communication.collective import all_gather, all_reduce, reduce_scatter
  from colossalai.legacy.context.parallel_mode import ParallelMode
  from colossalai.legacy.core import global_context
  from colossalai.utils import get_current_device
label_desc: Use image node_id 1 for calling the _ReduceScatterTensor2p5D obj's underlying member method code with example usage: obj.forward(ctx, input_, dim, parallel_mode) and returns: reduce_scatter