code: def AddDistributedBlobSync(model, blobs):
      """
      Sync blobs across machines (but not across devices)
      """
      if model._rendezvous is None:
          return
      synth_name = "_".join([str(b) for b in blobs])
      comm_world = _CreateOrCloneCommonWorld(
          model.param_init_net,
          "blob_sync_cw_" + synth_name,
          rendezvous=model._rendezvous,
      )
  
      model.net.Allreduce(
          inputs=[comm_world] + blobs,
          outputs=blobs,
          engine=model._rendezvous["engine"],
      )
  
imports: from collections import OrderedDict
  import logging
  import copy
  from multiprocessing import cpu_count
  from caffe2.python import model_helper, dyndep, scope, workspace, core, memonger, utils
  from caffe2.proto import caffe2_pb2
  import numpy
  import warnings
label_desc: Use image node_id 26 for calling a global function with example usage: AddDistributedBlobSync(model, blobs) without return types