class_docstr: Tests for VcfWriter with exclude_header=True.
docstr: Writes a headerless vcf and reads it back out.
docstr_tok: ["Writes","a","headerless","vcf","and","reads","it","back","out","."]
code: def test_headerless_vcf(self):
      """Writes a headerless vcf and reads it back out."""
      test_vcf = test_utils.genomics_core_testdata("test_sites.vcf")
      output_vcf = test_utils.test_tmpfile("output.vcf")
      expected_variants = []
      with vcf.VcfReader(test_vcf) as reader:
          with vcf.VcfWriter(
              output_vcf, header=reader.header, exclude_header=True
          ) as writer:
              for record in reader:
                  expected_variants.append(record)
                  writer.write(record)
  
          with vcf.VcfReader(
              output_vcf, header=reader.header
          ) as actual_reader:
              self.assertEqual(expected_variants, list(actual_reader))
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import absltest
  from absl.testing import parameterized
  from etils import epath
  from third_party.nucleus.io import vcf
  from third_party.nucleus.protos import reference_pb2
  from third_party.nucleus.protos import struct_pb2
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.testing import test_utils
  from third_party.nucleus.util import ranges
label_desc: Use image node_id 1 for calling the VcfWriterHeaderlessTests obj's underlying member method code with example usage: obj.test_headerless_vcf() without return types