docstr: Calculate the score
  
  :param str transformed_text: transformed sentence
  :param str reference_text: origin sentence
  :return float: the score of two sentence
code: def validate(self, transformed_text, reference_text):
      r"""
      Calculate the score
  
      :param str transformed_text: transformed sentence
      :param str reference_text: origin sentence
      :return float: the score of two sentence
  
      """
      if self.type == "bleu":
          return nltk.translate.bleu_score.sentence_bleu(
              [self.processor.tokenize(reference_text)],
              self.processor.tokenize(transformed_text),
          )
      elif self.type == "chrf":
          return nltk.translate.chrf_score.sentence_chrf(
              self.processor.tokenize(reference_text),
              self.processor.tokenize(transformed_text),
          )
  
      elif self.type == "meteor":
          return nltk.translate.meteor(
              [reference_text], transformed_text
          )
  
file_path: textflint/textflint/generation/validator/translate_score.py
imports: import nltk
  import nltk.translate.chrf_score
  from .validator import Validator
  from ...common.preprocess.en_processor import EnProcessor
label_desc: Use image node_id 3 for calling the TranslateScore obj's underlying member method code with example usage: obj.validate(transformed_text, reference_text) and returns: nltk, nltk, nltk