code: def test_iterate_bedgraph_reader(self, bedgraph_path):
      bedgraph_path = test_utils.genomics_core_testdata(bedgraph_path)
      expected = [
          ("chr1", 10, 20, 100),
          ("chr1", 100, 200, 250),
          ("chr1", 300, 400, 150.1),
          ("chr1", 500, 501, 20.13),
      ]
      with bedgraph.BedGraphReader(bedgraph_path) as reader:
          records = list(reader.iterate())
      self.assertLen(records, 4)
      self.assertEqual(
          [
              (r.reference_name, r.start, r.end, r.data_value)
              for r in records
          ],
          expected,
      )
  
file_path: deepvariant/third_party/nucleus/io/bedgraph_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import absltest
  from absl.testing import parameterized
  from third_party.nucleus.io import bedgraph
  from third_party.nucleus.protos import bedgraph_pb2
  from third_party.nucleus.testing import test_utils
label_desc: Use image node_id 1 for calling the BedGraphTests obj's underlying member method code with example usage: obj.test_iterate_bedgraph_reader(bedgraph_path) without return types