old_contents: import sys
  sys.path.append('..')
  import unittest
  import io
  import re
  
  from preprocessing import gen_lines, gen_batch, fill_batch
  from vocabulary import Vocabulary
  
  class PreprocessingTestCase(unittest.TestCase):
      def test_gen_lines(self):
          pass
  
      def test_gen_batch(self):
          lines = ['a', 'b', 'c']
          vocab = Vocabulary(lines, th=0)
          batches = gen_batch(lines, vocab, 3)
          lines = [[[1] + [vocab.wtoi[l]] + [2, -1]] for l in lines]
          for batch, line in zip(batches, lines):
              for b, l in zip(batch, line):
                  self.assertEqual(b, l)
  
      def test_fill_batch(self):
          lines= [[1, 2, 3], [1, 2]]
          batch = fill_batch(lines)
          self.assertEqual(batch[1][-1], -1)
  
new_contents: import sys
  sys.path.append('..')
  import unittest
  import io
  import re
  
  from preprocessing import gen_lines, line2batch, fill_batch
  from vocabulary import Vocabulary
  
  class PreprocessingTestCase(unittest.TestCase):
      def test_gen_lines(self):
          pass
  
      def test_line2batch(self):
          lines = ['a', 'b', 'c']
          vocab = Vocabulary(lines, th=0)
          batches = next(line2batch(lines, vocab, 3))[0].data
          lines = [[[1] + [vocab.wtoi[l]] + [2, -1]] for l in lines]
          for batch, line in zip(batches, lines):
              for b, l in zip(batch, line):
                  self.assertEqual(b, l)
  
      def test_fill_batch(self):
          lines= [[1, 2, 3], [1, 2]]
          batch = fill_batch(lines)
          self.assertEqual(batch[1][-1], -1)
  
subject: update test case for line2batch