code: def test_sample_name_flag(self):
      FLAGS.ref = testdata.CHR20_FASTA
      FLAGS.examples = testdata.GOLDEN_TRAINING_EXAMPLES
      FLAGS.sample_name = "sample_name"
      FLAGS.output_vcf = test_utils.test_tmpfile("no_sample_name.vcf")
  
      labeled_examples_to_vcf.main(0)
  
      with vcf.VcfReader(FLAGS.output_vcf) as vcf_reader:
          self.assertEqual(
              list(vcf_reader.header.sample_names), [FLAGS.sample_name]
          )
  
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 2 for calling the ExamplesToVCFUnitTest obj's underlying member method code with example usage: obj.test_sample_name_flag() without return types