code: def memory_reserved(self, device_index=None):
      if hasattr(torch.cuda, "memory_reserved"):
          return torch.cuda.memory_reserved(device_index)
  
imports: from deepspeed.accelerator.abstract_accelerator import DeepSpeedAccelerator
  import torch.cuda
label_desc: Use image node_id 31 for calling the CUDA_Accelerator obj's underlying member method code with example usage: obj.memory_reserved(device_index) and returns: torch