code: def test_multilabel_field_can_index_with_vocab(self):
      vocab = Vocabulary()
      vocab.add_token_to_namespace("rel0", namespace="rel_labels")
      vocab.add_token_to_namespace("rel1", namespace="rel_labels")
      vocab.add_token_to_namespace("rel2", namespace="rel_labels")
  
      f = MultiLabelField(
          ["rel1", "rel0"], label_namespace="rel_labels"
      )
      f.index(vocab)
      tensor = (
          f.as_tensor(f.get_padding_lengths()).detach().cpu().numpy()
      )
      numpy.testing.assert_array_almost_equal(
          tensor, numpy.array([1, 1, 0])
      )
  
imports: import logging
  import numpy
  import pytest
  from allennlp.common.checks import ConfigurationError
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data.fields import MultiLabelField
  from allennlp.data.vocabulary import Vocabulary
label_desc: Use image node_id 2 for calling the TestMultiLabelField obj's underlying member method code with example usage: obj.test_multilabel_field_can_index_with_vocab() without return types