old_contents: from __future__ import absolute_import, division
  
new_contents: import copy
  
  def transfer_weights(model_from, model_to):
      wf = copy.deepcopy(model_from.state_dict())
      wt = model_to.state_dict()
      for k in wt.keys():
          if not k in wf:
              wf[k] = wt[k]
      model_to.load_state_dict(wf)
  
subject: add transfer_weights