code: def test_iterate_bed_reader(self, bed_filename):
      bed_path = test_utils.genomics_core_testdata(bed_filename)
      expected = [("chr1", 10, 20), ("chr1", 100, 200)]
      with bed.BedReader(bed_path) as reader:
          records = list(reader.iterate())
      self.assertLen(records, 2)
      self.assertEqual(
          [(r.reference_name, r.start, r.end) for r in records],
          expected,
      )
  
file_path: deepvariant/third_party/nucleus/io/bed_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 bed
  from third_party.nucleus.io.python import bed_reader
  from third_party.nucleus.protos import bed_pb2
  from third_party.nucleus.testing import test_utils
label_desc: Use image node_id 2 for calling the BedReaderTests obj's underlying member method code with example usage: obj.test_iterate_bed_reader(bed_filename) without return types