code: def test_reserved_format_field_set_fn(self, field, expected):
      actual = vcf_constants.reserved_format_field_set_fn(field)
      self.assertIs(actual, expected)
  
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 third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.util import struct_utils
  from third_party.nucleus.util import vcf_constants
label_desc: Use image node_id 15 for calling the VcfConstantsTest obj's underlying member method code with example usage: obj.test_reserved_format_field_set_fn(field, expected) without return types