class_docstr: Bleu scorer.
class_docstr_tok: ["Bleu","scorer","."]
code: def score_ratio_str(self, option=None):
      return "%.4f (%.2f)" % self.score_ratio(option)
  
imports: import copy
  import math
  from builtins import dict, range
  from collections import defaultdict
label_desc: Use image node_id 6 for calling the BleuScorer obj's underlying member method code with example usage: obj.score_ratio_str(option) and returns: unknown