old_contents: # -*- coding: utf-8 -*-
  # Natural Language Toolkit: Machine Translation
  #
  # Copyright (C) 2001-2015 NLTK Project
  # Author: Steven Bird <stevenbird1@gmail.com>, Tah Wei Hoon <hoon.tw@gmail.com>
  # URL: <http://nltk.org/>
  # For license information, see LICENSE.TXT
  
  """
  Experimental features for machine translation.
  These interfaces are prone to change.
  """
  
  from nltk.translate.api import AlignedSent, Alignment, PhraseTable
  from nltk.translate.ibm_model import IBMModel
  from nltk.translate.ibm1 import IBMModel1
  from nltk.translate.ibm2 import IBMModel2
  from nltk.translate.ibm3 import IBMModel3
  from nltk.translate.ibm4 import IBMModel4
  from nltk.translate.ibm5 import IBMModel5
  from nltk.translate.sentence_bleu import bleu
  from nltk.translate.ribes_score import ribes
  from nltk.translate.metrics import alignment_error_rate
  from nltk.translate.stack_decoder import StackDecoder
  
new_contents: # -*- coding: utf-8 -*-
  # Natural Language Toolkit: Machine Translation
  #
  # Copyright (C) 2001-2015 NLTK Project
  # Author: Steven Bird <stevenbird1@gmail.com>, Tah Wei Hoon <hoon.tw@gmail.com>
  # URL: <http://nltk.org/>
  # For license information, see LICENSE.TXT
  
  """
  Experimental features for machine translation.
  These interfaces are prone to change.
  """
  
  from nltk.translate.api import AlignedSent, Alignment, PhraseTable
  from nltk.translate.ibm_model import IBMModel
  from nltk.translate.ibm1 import IBMModel1
  from nltk.translate.ibm2 import IBMModel2
  from nltk.translate.ibm3 import IBMModel3
  from nltk.translate.ibm4 import IBMModel4
  from nltk.translate.ibm5 import IBMModel5
  from nltk.translate.bleu_score import sentence_bleu as bleu
  from nltk.translate.ribes_score import ribes
  from nltk.translate.metrics import alignment_error_rate
  from nltk.translate.stack_decoder import StackDecoder
  
subject: correct the imports for sentence_bleu as nltk.translate.bleu