code: def test_expand_raises_on_negative_n_bp(self):
      with self.assertRaisesRegexp(
          ValueError, "n_bp must be >= 0 but got -10"
      ):
          ranges.expand(ranges.make_range("1", 10, 20), -10)
  
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 43 for calling the RangesTests obj's underlying member method code with example usage: obj.test_expand_raises_on_negative_n_bp() without return types