code: def test_from_regions_empty_literals(self):
      range_set = ranges.RangeSet.from_regions([])
      # The set is empty.
      self.assertItemsEqual([], range_set)
      self.assertFalse(range_set)
  
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 4 for calling the RangesTests obj's underlying member method code with example usage: obj.test_from_regions_empty_literals() without return types