code: def test_padding_lengths_are_computed_correctly(self):
      field = TextField(
          [Token(t) for t in ["This", "is", "a", "sentence", "."]],
          token_indexers={"words": SingleIdTokenIndexer("words")},
      )
      field.index(self.vocab)
      padding_lengths = field.get_padding_lengths()
      assert padding_lengths == {"num_tokens": 5}
  
      field = TextField(
          [Token(t) for t in ["This", "is", "a", "sentence", "."]],
          token_indexers={
              "characters": TokenCharactersIndexer("characters")
          },
      )
      field.index(self.vocab)
      padding_lengths = field.get_padding_lengths()
      assert padding_lengths == {
          "num_tokens": 5,
          "num_token_characters": 8,
      }
  
      field = TextField(
          [Token(t) for t in ["This", "is", "a", "sentence", "."]],
          token_indexers={
              "characters": TokenCharactersIndexer("characters"),
              "words": SingleIdTokenIndexer("words"),
          },
      )
      field.index(self.vocab)
      padding_lengths = field.get_padding_lengths()
      assert padding_lengths == {
          "num_tokens": 5,
          "num_token_characters": 8,
      }
  
imports: from __future__ import with_statement
  from __future__ import absolute_import
  from __future__ import print_function
  from collections import defaultdict
  import pytest
  import numpy
  from allennlp.data import Token, Vocabulary
  from allennlp.data.fields import TextField
  from allennlp.data.token_indexers import SingleIdTokenIndexer, TokenCharactersIndexer, TokenIndexer
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.common.checks import ConfigurationError
  from allennlp.common.util import pad_sequence_to_length
label_desc: Use image node_id 5 for calling the TestTextField obj's underlying member method code with example usage: obj.test_padding_lengths_are_computed_correctly() without return types