code: def test_lr_finder_with_ddp(tmpdir):
      seed_everything(7)
  
      init_lr = 1e-4
      dm = ClassifDataModule()
      model = ClassificationModel(lr=init_lr)
  
      trainer = Trainer(
          default_root_dir=tmpdir,
          max_epochs=1,
          strategy="ddp",
          devices=2,
          accelerator="cpu",
      )
  
      tuner = Tuner(trainer)
      tuner.lr_find(
          model, datamodule=dm, update_attr=True, num_training=20
      )
      lr = trainer.lightning_module.lr
      lr = trainer.strategy.broadcast(lr)
      assert trainer.lightning_module.lr == lr
      assert lr != init_lr
  
imports: import logging
  import math
  import os
  from copy import deepcopy
  from typing import Any
  from unittest import mock
  import pytest
  import torch
  from lightning.pytorch import Trainer, seed_everything
  from lightning.pytorch.callbacks.lr_finder import LearningRateFinder
  from lightning.pytorch.demos.boring_classes import BoringModel
  from lightning.pytorch.tuner.lr_finder import _LRFinder
  from lightning.pytorch.tuner.tuning import Tuner
  from lightning.pytorch.utilities.exceptions import MisconfigurationException
  from lightning.pytorch.utilities.types import STEP_OUTPUT
  from lightning_utilities.test.warning import no_warning_call
  from tests_pytorch.helpers.datamodules import ClassifDataModule
  from tests_pytorch.helpers.runif import RunIf
  from tests_pytorch.helpers.simple_models import ClassificationModel
  from tests_pytorch.helpers.utils import getattr_recursive
label_desc: Use image node_id 18 for calling a global function with example usage: test_lr_finder_with_ddp(tmpdir) without return types