code: def _signal(self):
      if self.should_signal:
          # simulate `os.kill(os.getpid(), signal.SIGTERM)`
          self.trainer._signal_connector.received_sigterm = True
  
imports: import inspect
  import pytest
  from lightning.fabric.utilities.seed import seed_everything
  from lightning.pytorch import Callback, Trainer
  from lightning.pytorch.callbacks import OnExceptionCheckpoint
  from lightning.pytorch.demos.boring_classes import BoringModel, RandomDataset
  from lightning.pytorch.utilities.exceptions import SIGTERMException
  from torch.utils.data.dataloader import DataLoader
  from tests_pytorch.helpers.runif import RunIf
label_desc: Use image node_id 2 for calling the TestAutoRestartModelUnderSignal obj's underlying member method code with example usage: obj._signal() without return types