code: def test_is_heterozygous(self, genotype, expected):
      call = variants_pb2.VariantCall(genotype=genotype)
      actual = variantcall_utils.is_heterozygous(call)
      self.assertEqual(actual, expected)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import functools
  from absl.testing import absltest
  from absl.testing import parameterized
  import mock
  from third_party.nucleus.protos import struct_pb2
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.util import struct_utils
  from third_party.nucleus.util import variantcall_utils
label_desc: Use image node_id 9 for calling the VariantcallUtilsTests obj's underlying member method code with example usage: obj.test_is_heterozygous(genotype, expected) without return types