code: def device_name(self, device_index=None):
      if device_index is None:
          return "npu"
      return "npu:{}".format(device_index)
  
imports: import importlib
  import inspect
  from .abstract_accelerator import DeepSpeedAccelerator
label_desc: Use image node_id 3 for calling the NPU_Accelerator obj's underlying member method code with example usage: obj.device_name(device_index) and returns: str, str