class_docstr: Bleu scorer.
class_docstr_tok: ["Bleu","scorer","."]
docstr: called by constructor and __iadd__ to avoid creating new instances.
docstr_tok: ["called","by","constructor","and","__iadd__","to","avoid","creating","new","instances","."]
code: def cook_append(self, test, refs):
      """called by constructor and __iadd__ to avoid creating new instances."""
  
      if refs is not None:
          self.crefs.append(cook_refs(refs))
          if test is not None:
              cooked_test = cook_test(test, self.crefs[-1])
              self.ctest.append(cooked_test)  # N.B.: -1
          else:
              self.ctest.append(
                  None
              )  # lens of crefs and ctest have to match
  
      self._score = None
  
imports: import copy
  import math
  from builtins import dict, range
  from collections import defaultdict
label_desc: Use image node_id 3 for calling the BleuScorer obj's underlying member method code with example usage: obj.cook_append(test, refs) without return types