code: def synchronize(self, device_index=None):
      return self.hpu.synchronize()
  
imports: import os
  import pkgutil
  import importlib
  import torch
  from .abstract_accelerator import DeepSpeedAccelerator
label_desc: Use image node_id 9 for calling the HPU_Accelerator obj's underlying member method code with example usage: obj.synchronize(device_index) and returns: self