class_docstr: Tests the bleu functions.
      
class_docstr_tok: ["Tests","the","bleu","functions","."]
code: def _test_corpus_bleu(
      self,
      list_of_references,
      hypotheses,
      lowercase,
      return_all,
      true_bleu,
  ):
      bleu = corpus_bleu_moses(
          list_of_references=list_of_references,
          hypotheses=hypotheses,
          lowercase=lowercase,
          return_all=return_all,
      )
      if not return_all:
          self.assertAlmostEqual(bleu, true_bleu, places=2)
      else:
          for ret, true in zip(bleu, true_bleu):
              self.assertAlmostEqual(ret, true, places=2)
  
      bleu = corpus_bleu(
          list_of_references=list_of_references,
          hypotheses=hypotheses,
          lowercase=lowercase,
          return_all=return_all,
      )
      if not return_all:
          self.assertAlmostEqual(bleu, true_bleu, places=0)
      else:
          for ret, true in zip(bleu, true_bleu):
              self.assertAlmostEqual(ret, true, places=0)
  
file_path: texar/tests/evals/bleu_test.py
imports: import numpy
  import tensorflow
  from texar.tf.evals.bleu_moses import sentence_bleu_moses, corpus_bleu_moses
  from texar.tf.evals.bleu import sentence_bleu, corpus_bleu
label_desc: Use image node_id 6 for calling the BLEUTest obj's underlying member method code with example usage: obj._test_corpus_bleu(list_of_references, hypotheses, lowercase, return_all, true_bleu) without return types