code: def test_padded_everygram_pipeline(self):
      expected_train = [
          [
              ("<s>",),
              ("<s>", "a"),
              ("a",),
              ("a", "b"),
              ("b",),
              ("b", "c"),
              ("c",),
              ("c", "</s>"),
              ("</s>",),
          ]
      ]
      expected_vocab = ["<s>", "a", "b", "c", "</s>"]
      train_data, vocab_data = padded_everygram_pipeline(
          2, [["a", "b", "c"]]
      )
      self.assertEqual(
          [list(sent) for sent in train_data], expected_train
      )
      self.assertEqual(list(vocab_data), expected_vocab)
  
imports: import unittest
  from nltk.lm.preprocessing import padded_everygram_pipeline
label_desc: Use image node_id 1 for calling the TestPreprocessing obj's underlying member method code with example usage: obj.test_padded_everygram_pipeline() without return types