class_docstr: A class for tracking BLEU (https://www.aclweb.org/anthology/P02-1040.pdf).
  Arguments
  ---------
  merge_words: bool
      Whether to merge the successive words to create sentences.
  Example
  -------
  >>> bleu = BLEUStats()
  >>> i2l = {0: 'a', 1: 'b'}
  >>> bleu.append(
  ...     ids=['utterance1'],
  ...     predict=[[0, 1, 1]],
  ...     targets=[[[0, 1, 0]], [[0, 1, 1]], [[1, 1, 0]]],
  ...     ind2lab=lambda batch: [[i2l[int(x)] for x in seq] for seq in batch],
  ... )
  >>> stats = bleu.summarize()
  >>> stats['BLEU']
  0.0
docstr: Write all relevant info (e.g., error rate alignments) to file.
  * See MetricStats.write_stats()
docstr_tok: ["Write","all","relevant","info","(","e.g.",",","error","rate","alignments",")","to","file",".","*","See","MetricStats.write_stats","(",")"]
code: def write_stats(self, filestream):
      """Write all relevant info (e.g., error rate alignments) to file.
      * See MetricStats.write_stats()
      """
      if not self.summary:
          self.summarize()
  
      print(self.scores, file=filestream)
  
imports: from speechbrain.utils.metric_stats import MetricStats
label_desc: Use image node_id 4 for calling the BLEUStats obj's underlying member method code with example usage: obj.write_stats(filestream) without return types