code: def fork(input: Tensor) -> Tuple[Tensor, Tensor]:
      """Branches out from an autograd lane of the given tensor."""
      if torch.is_grad_enabled() and input.requires_grad:
          input, phony = Fork.apply(input)
      else:
          phony = get_phony(input.device, requires_grad=False)
  
      return input, phony
  
file_path: pytorch/torch/distributed/pipeline/sync/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 a global function with example usage: fork(input) and returns: input,  phony