code: def forward(
      ctx: Any,
      group: dist.ProcessGroup,
      input: Tensor,
      scatter_idx: int,
      gather_idx: int,
  ) -> Tensor:
      ctx.group = group
      ctx.scatter_idx = scatter_idx
      ctx.gather_idx = gather_idx
  
      return single_all_to_all(input, scatter_idx, gather_idx, group)
  
file_path: DeepSpeed/deepspeed/sequence/layer.py
imports: import torch
  from typing import Any, Tuple
  from torch import Tensor
  from torch.nn import Module
  import deepspeed.comm
label_desc: Use image node_id 1 for calling the _SeqAllToAll obj's underlying member method code with example usage: obj.forward(ctx, group, input, scatter_idx, gather_idx) and returns: single_all_to_all