code: def _find_device(self) -> None:
      global_rank = os.getenv("DATA_OPTIMIZER_GLOBAL_RANK", None)
      if torch.cuda.is_available() and global_rank:
          num_gpus = torch.cuda.device_count()
          device = int(global_rank) % num_gpus
          self._device = f"cuda:{device}"
  
imports: import inspect
  import os
  from datetime import datetime
  from pathlib import Path
  from types import FunctionType
  from typing import Any, Callable, Dict, Optional, Sequence, Union
  import torch
  from lightning.data.streaming.constants import _LIGHTNING_CLOUD_LATEST, _TORCH_GREATER_EQUAL_2_1_0
  from lightning.data.streaming.data_processor import DataChunkRecipe, DataProcessor, DataTransformRecipe
label_desc: Use image node_id 4 for calling the LambdaDataTransformRecipe obj's underlying member method code with example usage: obj._find_device() without return types