code: def device_type(self) -> str:
      if self.chunk_temp is not None:
          return self.chunk_temp.device.type
      else:
          if self.is_gathered or self.cuda_shard is not None:
              return "npu" if IS_NPU_AVAILABLE else "cuda"
          else:
              return "cpu"
  
imports: from dataclasses import dataclass
  from enum import Enum
  from typing import Dict, List, Optional
  import torch
  import torch.distributed
  from torch.distributed import ProcessGroup
  from colossalai.utils import get_current_device
  from colossalai.utils.device import IS_NPU_AVAILABLE
label_desc: Use image node_id 3 for calling the Chunk obj's underlying member method code with example usage: obj.device_type() and returns: self, unknown, str