code: def device(self) -> torch.device:
      device = self._device
  
      # make this more explicit to always include the index
      if device.type == "cuda" and device.index is None:
          return torch.device(f"cuda:{torch.cuda.current_device()}")
  
      return device
  
file_path: pytorch-lightning/src/lightning/fabric/utilities/device_dtype_mixin.py
imports: from typing import Any, List, Optional, Union
  import torch
  from torch.nn import Module
  from typing_extensions import Self, override
label_desc: Use image node_id 4 for calling the _DeviceDtypeModuleMixin obj's underlying member method code with example usage: obj.device() and returns: device, torch