code: def test_match_selects_variant_by_start(self):
      # Tests that match() selects the variant at the same start even if that
      # variant doesn't have the same alleles at candidate and there's an
      # overlapping with the same alleles.
      overlapping = [
          test_utils.make_variant(
              start=20, alleles=["CC", "A"], gt=[1, 1]
          ),
          test_utils.make_variant(
              start=21, alleles=["AAA", "A"], gt=[0, 1]
          ),
          test_utils.make_variant(
              start=22, alleles=["AA", "A"], gt=[1, 1]
          ),
      ]
      candidate = test_utils.make_variant(start=21, alleles=["CC", "A"])
  
      labeler = self._make_labeler(
          overlapping,
          ranges.RangeSet(
              [ranges.make_range(overlapping[0].reference_name, 0, 100)]
          ),
      )
      is_confident, truth_variant = labeler._match(candidate)
      self.assertEqual(is_confident, True)
      self.assertEqual(truth_variant, overlapping[1])
  
file_path: deepvariant/deepvariant/labeler/positional_labeler_test.py
imports: from absl.testing import absltest
  from absl.testing import parameterized
  from third_party.nucleus.io import vcf
  from third_party.nucleus.testing import test_utils
  from third_party.nucleus.util import ranges
  from deepvariant import testdata
  from deepvariant.labeler import positional_labeler
label_desc: Use image node_id 3 for calling the PositionalVariantLabelerTest obj's underlying member method code with example usage: obj.test_match_selects_variant_by_start() without return types