code: def test_from_contigs(self):
      contigs = [
          reference_pb2.ContigInfo(name="chr1", n_bases=10),
          reference_pb2.ContigInfo(name="chr2", n_bases=5),
      ]
      self.assertCountEqual(
          [
              ranges.make_range("chr1", 0, 10),
              ranges.make_range("chr2", 0, 5),
          ],
          ranges.RangeSet.from_contigs(contigs),
      )
  
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 25 for calling the RangesTests obj's underlying member method code with example usage: obj.test_from_contigs() without return types