code: def forward(self, input):
      skip = yield pop("skip")
      return input + skip
  
file_path: pytorch/test/distributed/pipeline/sync/skip/test_leak.py
imports: import pytest
  import torch
  from torch import nn
  from torch.distributed.pipeline.sync import Pipe, is_checkpointing, is_recomputing
  from torch.distributed.pipeline.sync.skip import pop, skippable, stash
  from torch.distributed.pipeline.sync.skip.tracker import current_skip_tracker
  from torch.testing._internal.common_utils import run_tests
label_desc: Use image node_id 1 for calling the Pop obj's underlying member method code with example usage: obj.forward(input) and returns: unknown