class_docstr: An accumulator object capable of computing BLEU score using multiple references.
  The BLEU score is always smoothed a bit so that it's never undefined. For sentence-level
  measurements, proper smoothing should be used via the smoothing parameter (set to 1.0 for
  the same behavior as default Moses's MERT sentence BLEU).
docstr: Reset the object, zero all counters.
docstr_tok: ["Reset","the","object",",","zero","all","counters","."]
code: def reset(self):
      """Reset the object, zero all counters."""
      self.ref_len = 0
      self.cand_lens = [0] * self.max_ngram
      self.hits = [0] * self.max_ngram
  
imports: from __future__ import unicode_literals
  from __future__ import division
  from builtins import zip
  from builtins import range
  from past.utils import old_div
  from builtins import object
  from collections import defaultdict
  import math
  import re
label_desc: Use image node_id 2 for calling the BLEUScore obj's underlying member method code with example usage: obj.reset() without return types