code: def test_ops_on_closed_reader_raise(self):
      reader = bed_reader.BedReader.from_file(self.bed, self.options)
      with reader:
          pass
      # At this point the reader is closed.
      with self.assertRaisesRegexp(
          ValueError, "Cannot Iterate a closed"
      ):
          reader.iterate()
  
file_path: deepvariant/third_party/nucleus/io/python/bed_reader_wrap_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 clif_postproc
  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 4 for calling the BedReaderTest obj's underlying member method code with example usage: obj.test_ops_on_closed_reader_raise() without return types