code: def test_label_from_example(self, truth_label):
      feature = {"label": _int_feature([truth_label])}
      example = example_pb2.Example(
          features=feature_pb2.Features(feature=feature)
      )
      output = vis.label_from_example(example)
      self.assertEqual(truth_label, output)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import glob
  import os
  from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.testing import test_utils
  from third_party.nucleus.util import vis
  from tensorflow.core.example import example_pb2
  from tensorflow.core.example import feature_pb2
label_desc: Use image node_id 18 for calling the VisTest obj's underlying member method code with example usage: obj.test_label_from_example(truth_label) without return types