code: def test_has_already_handler(handler, expected_return):
      """Test that the SignalConnector detects whether a signal handler is already attached."""
      with mock.patch(
          "lightning.pytorch.trainer.connectors.signal_connector.signal.getsignal",
          return_value=handler,
      ):
          assert (
              _SignalConnector._has_already_handler(signal.SIGTERM)
              is expected_return
          )
  
imports: import concurrent.futures
  import os
  import signal
  from unittest import mock
  from unittest.mock import Mock
  import pytest
  from lightning.fabric.plugins.environments import SLURMEnvironment
  from lightning.fabric.utilities.imports import _IS_WINDOWS
  from lightning.pytorch import Trainer
  from lightning.pytorch.demos.boring_classes import BoringModel
  from lightning.pytorch.trainer.connectors.signal_connector import _SignalConnector
  from lightning.pytorch.utilities.exceptions import SIGTERMException
  from tests_pytorch.helpers.runif import RunIf
label_desc: Use image node_id 10 for calling a global function with example usage: test_has_already_handler(handler, expected_return) without return types