old_contents: from __future__ import unicode_literals
  from ...tokens import Doc
  from ...vocab import Vocab
  
  
  def test_issue600():
      doc = Doc(Vocab(tag_map={'NN': {'pos': 'NOUN'}}), words=['hello'])
      doc[0].tag_ = u'NN'
  
new_contents: from __future__ import unicode_literals
  from ...tokens import Doc
  from ...vocab import Vocab
  from ...attrs import POS
  
  
  def test_issue600():
      doc = Doc(Vocab(tag_map={'NN': {'pos': 'NOUN'}}), words=['hello'])
      doc[0].tag_ = u'NN'
  
subject: Add import in regression test