code: def synchronize(tensor, dist_opt):
      dist_opt.all_reduce(tensor.data)
      dist_opt.wait()
      tensor /= dist_opt.world_size
  
imports: from singa import singa_wrap
  from singa import autograd
  from singa import tensor
  from singa import device
  from singa import opt
  from PIL import Image
  import numpy
  import os
  import sys
  import time
label_desc: Use image node_id 11 for calling a global function with example usage: synchronize(tensor, dist_opt) without return types