code: def __init__(self, lower_split=False):
      def preproc(text):
          if lower_split:
              return text.lower().split()
          else:
              return text
  
      # BLEU Paper examples
      self.cand_1 = preproc("the the the the the the the")
      self.ref_1a = preproc("The cat is on the mat")
      self.ref_1b = preproc("There is a cat on the mat")
  
      self.cand_2a = preproc(
          "It is a guide to action which ensures that the military always obeys the commands of the party"
      )
      self.cand_2b = preproc(
          "It is to insure the troops forever hearing the activity guidebook that "
          "party direct"
      )
      self.ref_2a = preproc(
          "It is a guide to action that ensures that the military will forever heed "
          "Party commands"
      )
      self.ref_2b = preproc(
          "It is the guiding principle which guarantees the military forces always being under the command of "
          "the Party"
      )
      self.ref_2c = preproc(
          "It is the practical guide for the army always to heed the directions of the party"
      )
  
      self.cand_3 = preproc("of the")
  
      self.references_1 = [self.ref_1a, self.ref_1b]
      self.references_2 = [self.ref_2a, self.ref_2b, self.ref_2c]
  
      self.sample_1 = ([self.cand_1], [self.references_1])
      self.sample_2 = ([self.cand_3], [self.references_2])
      self.sample_3 = ([self.cand_2a], [self.references_2])
      self.sample_4 = ([self.cand_2b], [self.references_2])
      self.sample_5 = (
          [self.cand_2a, self.cand_2b],
          [self.references_2, self.references_2],
      )
  
      self.references_3 = [self.ref_2a, self.ref_2b]
      self.references_4 = [self.ref_2b, self.ref_2c]
      self.references_5 = [self.ref_2a, self.ref_2c]
  
      self.chunks = [
          ([self.cand_1], [self.references_1]),
          ([self.cand_2a], [self.references_2]),
          ([self.cand_2b], [self.references_2]),
          ([self.cand_1], [[self.ref_1a]]),
          ([self.cand_2a], [self.references_3]),
          ([self.cand_2b], [self.references_3]),
          ([self.cand_1], [[self.ref_1b]]),
          ([self.cand_2a], [self.references_4]),
          ([self.cand_2b], [self.references_4]),
          ([self.cand_1], [self.references_1]),
          ([self.cand_2a], [self.references_5]),
          ([self.cand_2b], [self.references_5]),
          ([self.cand_1], [[self.ref_1a]]),
          ([self.cand_2a], [[self.ref_2a]]),
          ([self.cand_2b], [[self.ref_2c]]),
      ]
  
label_desc: Use image node_id 1 to create a new CorpusForTest object  with example: obj = CorpusForTest(lower_split)