code: def _add_class_to_variant(variant, class_status):
      if class_status is None:
          return variant
  
      header = variants_pb2.VcfHeader(
          infos=[
              variants_pb2.VcfInfo(
                  id=CUSTOMIZED_INFO_FIELD_NAME,
                  number="A",
                  type=vcf_constants.STRING_TYPE,
                  description="Customized class label for the variant.",
              )
          ]
      )
      my_cache = vcf.VcfHeaderCache(header)
      vcf_object = FakeVCFObject(field_access_cache=my_cache)
      variant_utils.set_info(
          variant,
          CUSTOMIZED_INFO_FIELD_NAME,
          class_status,
          vcf_object=vcf_object,
      )
      return variant
  
file_path: deepvariant/deepvariant/labeler/customized_classes_labeler_test.py
imports: import collections
  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 third_party.nucleus.util import variant_utils
  from deepvariant import testdata
  from deepvariant.labeler import customized_classes_labeler
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.util import vcf_constants
label_desc: Use image node_id 2 for calling a global function with example usage: _add_class_to_variant(variant, class_status) and returns: variant, variant