code: def test_invalid_reserved_format_field_get_fn(self, field):
      with self.assertRaisesRegexp(
          ValueError, "Unknown reserved FORMAT field to get:"
      ):
          vcf_constants.reserved_format_field_get_fn(field)
  
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 18 for calling the VcfConstantsTest obj's underlying member method code with example usage: obj.test_invalid_reserved_format_field_get_fn(field) without return types