code: def test_field_counts_vocab_items_correctly(self):
      field = TextField(
          [Token(t) for t in ["This", "is", "a", "sentence", "."]],
          token_indexers={"words": SingleIdTokenIndexer("words")},
      )
      namespace_token_counts = defaultdict(lambda: defaultdict(int))
      field.count_vocab_items(namespace_token_counts)
  
      assert namespace_token_counts["words"]["This"] == 1
      assert namespace_token_counts["words"]["is"] == 1
      assert namespace_token_counts["words"]["a"] == 1
      assert namespace_token_counts["words"]["sentence"] == 1
      assert namespace_token_counts["words"]["."] == 1
      assert list(namespace_token_counts.keys()) == ["words"]
  
      field = TextField(
          [Token(t) for t in ["This", "is", "a", "sentence", "."]],
          token_indexers={
              "characters": TokenCharactersIndexer("characters")
          },
      )
      namespace_token_counts = defaultdict(lambda: defaultdict(int))
      field.count_vocab_items(namespace_token_counts)
  
      assert namespace_token_counts["characters"]["T"] == 1
      assert namespace_token_counts["characters"]["h"] == 1
      assert namespace_token_counts["characters"]["i"] == 2
      assert namespace_token_counts["characters"]["s"] == 3
      assert namespace_token_counts["characters"]["a"] == 1
      assert namespace_token_counts["characters"]["e"] == 3
      assert namespace_token_counts["characters"]["n"] == 2
      assert namespace_token_counts["characters"]["t"] == 1
      assert namespace_token_counts["characters"]["c"] == 1
      assert namespace_token_counts["characters"]["."] == 1
      assert list(namespace_token_counts.keys()) == ["characters"]
  
      field = TextField(
          [Token(t) for t in ["This", "is", "a", "sentence", "."]],
          token_indexers={
              "words": SingleIdTokenIndexer("words"),
              "characters": TokenCharactersIndexer("characters"),
          },
      )
      namespace_token_counts = defaultdict(lambda: defaultdict(int))
      field.count_vocab_items(namespace_token_counts)
      assert namespace_token_counts["characters"]["T"] == 1
      assert namespace_token_counts["characters"]["h"] == 1
      assert namespace_token_counts["characters"]["i"] == 2
      assert namespace_token_counts["characters"]["s"] == 3
      assert namespace_token_counts["characters"]["a"] == 1
      assert namespace_token_counts["characters"]["e"] == 3
      assert namespace_token_counts["characters"]["n"] == 2
      assert namespace_token_counts["characters"]["t"] == 1
      assert namespace_token_counts["characters"]["c"] == 1
      assert namespace_token_counts["characters"]["."] == 1
      assert namespace_token_counts["words"]["This"] == 1
      assert namespace_token_counts["words"]["is"] == 1
      assert namespace_token_counts["words"]["a"] == 1
      assert namespace_token_counts["words"]["sentence"] == 1
      assert namespace_token_counts["words"]["."] == 1
      assert set(namespace_token_counts.keys()) == set(
          ["words", "characters"]
      )
  
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 2 for calling the TestTextField obj's underlying member method code with example usage: obj.test_field_counts_vocab_items_correctly() without return types