code: def test_make_population_vcf_readers_raises_on_shared_chromosomes(
      self,
  ):
      filenames = [
          testdata.AF_VCF_CHR20,
          testdata.AF_VCF_CHR21,
          testdata.AF_VCF_CHR20_AND_21,
      ]
  
      with self.assertRaisesRegex(
          expected_exception=ValueError,
          expected_regex="Variants on chr20 are included in multiple VCFs",
      ):
          allele_frequency.make_population_vcf_readers(filenames)
  
file_path: deepvariant/deepvariant/allele_frequency_test.py
imports: from absl.testing import absltest
  from absl.testing import parameterized
  from third_party.nucleus.io import fasta
  from third_party.nucleus.io import vcf
  from third_party.nucleus.protos import variants_pb2
  from deepvariant import allele_frequency
  from deepvariant import testdata
  from deepvariant.protos import deepvariant_pb2
label_desc: Use image node_id 6 for calling the AlleleFrequencyTest obj's underlying member method code with example usage: obj.test_make_population_vcf_readers_raises_on_shared_chromosomes() without return types