code: def test_raises_for_unlabeled_examples(self):
      FLAGS.ref = testdata.CHR20_FASTA
      FLAGS.examples = testdata.GOLDEN_CALLING_EXAMPLES
      FLAGS.output_vcf = test_utils.test_tmpfile("unlabeled.vcf")
  
      with self.assertRaisesRegex(
          ValueError,
          (
              "Variant .* does not have any genotypes. This tool only works with "
              "variants that have been labeled"
          ),
      ):
          labeled_examples_to_vcf.main(0)
  
file_path: deepvariant/deepvariant/labeler/labeled_examples_to_vcf_test.py
imports: from absl import flags
  from absl.testing import absltest
  from absl.testing import flagsaver
  from absl.testing import parameterized
  from third_party.nucleus.io import vcf
  from third_party.nucleus.testing import test_utils
  from deepvariant import testdata
  from deepvariant.labeler import labeled_examples_to_vcf
label_desc: Use image node_id 3 for calling the ExamplesToVCFUnitTest obj's underlying member method code with example usage: obj.test_raises_for_unlabeled_examples() without return types