code: def test_nested_list_fields_are_padded_correctly(self):
      nested_field1 = ListField(
          [LabelField(c) for c in ["a", "b", "c", "d", "e"]]
      )
      nested_field2 = ListField(
          [LabelField(c) for c in ["f", "g", "h", "i", "j", "k"]]
      )
      list_field = ListField(
          [nested_field1.empty_field(), nested_field1, nested_field2]
      )
      list_field.index(self.vocab)
      padding_lengths = list_field.get_padding_lengths()
      assert padding_lengths == {"num_fields": 3, "list_num_fields": 6}
      tensor = (
          list_field.as_tensor(padding_lengths).detach().cpu().numpy()
      )
      numpy.testing.assert_almost_equal(
          tensor,
          [
              [-1, -1, -1, -1, -1, -1],
              [0, 1, 2, 3, 4, -1],
              [5, 6, 7, 8, 9, 10],
          ],
      )
  
imports: from typing import Dict
  import numpy
  import torch
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data import Token, Vocabulary, Instance
  from allennlp.data.fields import TextField, LabelField, ListField, IndexField, SequenceLabelField
  from allennlp.data.token_indexers import SingleIdTokenIndexer, TokenCharactersIndexer
  from allennlp.data.data_loaders import SimpleDataLoader
  from allennlp.data.tokenizers import SpacyTokenizer
  from allennlp.models import Model
  from allennlp.modules import Embedding
  from allennlp.modules.text_field_embedders import BasicTextFieldEmbedder
label_desc: Use image node_id 7 for calling the TestListField obj's underlying member method code with example usage: obj.test_nested_list_fields_are_padded_correctly() without return types