code: def test_group_overlapping_variants(self, variants, expected):
      actual = haplotypes._group_overlapping_variants(variants)
      self.assertIsInstance(actual, types.GeneratorType)
      actual_list = list(actual)
      self.assertEqual(actual_list, expected)
  
imports: import types
  from absl import flags
  from absl.testing import absltest
  from absl.testing import flagsaver
  from absl.testing import parameterized
  import numpy
  from third_party.nucleus.testing import test_utils
  from deepvariant import haplotypes
label_desc: Use image node_id 4 for calling the ResolveOverlappingVariantsTest obj's underlying member method code with example usage: obj.test_group_overlapping_variants(variants, expected) without return types