code: def get_cuda_visible_devices():
      
      gpu_ids_str = os.environ.get("CUDA_VISIBLE_DEVICES", None)
  
      if gpu_ids_str is None:
          return None
  
      if gpu_ids_str == "":
          return []
  
      return [int(i) for i in gpu_ids_str.split(",")]
docs: Get the device IDs in the CUDA_VISIBLE_DEVICES environment variable.
  
      Returns:
          if CUDA_VISIBLE_DEVICES is set, this returns a list of integers with
              the IDs of the GPUs. If it is not set, this returns None.