code: def test_expand_is_correct(self, region, n_bp, contig_map, expected):
      self.assertEqual(
          expected, ranges.expand(region, n_bp, contig_map)
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import itertools
  from absl.testing import absltest
  from absl.testing import parameterized
  import mock
  from third_party.nucleus.protos import position_pb2
  from third_party.nucleus.protos import reference_pb2
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.testing import test_utils
  from third_party.nucleus.util import ranges
label_desc: Use image node_id 41 for calling the RangesTests obj's underlying member method code with example usage: obj.test_expand_is_correct(region, n_bp, contig_map, expected) without return types