code: def test_lookup_2d(self):
      self.assertEqual(
          [[1, 0, 3, 4], [], [2]],
          self.vocab.lookup_indices_2d(
              [["a", "e", "c", "d"], [], ["b"]]
          ),
      )
      self.assertEqual([], self.vocab.lookup_indices_2d([]))
  
file_path: pytext/pytext/torchscript/tests/test_vocab.py
imports: import unittest
  import torch
  from pytext.torchscript.vocab import ScriptVocabulary
  from torch import jit
label_desc: Use image node_id 5 for calling the VocabTest obj's underlying member method code with example usage: obj.test_lookup_2d() without return types