code: def forward(ctx: "Fork", input: Tensor) -> Tuple[Tensor, Tensor]:  # type: ignore
      phony = get_phony(input.device, requires_grad=False)
      return input.detach(), phony.detach()
  
file_path: fairscale/fairscale/nn/pipe/dependency.py
imports: from typing import List, Tuple
  import torch
  from torch import Tensor
  from .phony import get_phony
label_desc: Use image node_id 1 for calling the Fork obj's underlying member method code with example usage: obj.forward(ctx, input) and returns: input,  phony