class_docstr: Test io.SamReader on CRAM formatted files.
code: def _make_reader(self, filename, has_embedded_ref):
      if has_embedded_ref:
          # If we have an embedded reference, force the reader to use it by not
          # providing an argument for ref_path.
          return sam.SamReader(
              test_utils.genomics_core_testdata(filename)
          )
      else:
          # Otherwise we need to explicitly override the reference encoded in the UR
          # of the CRAM file to use the path provided to our test.fasta.
          return sam.SamReader(
              test_utils.genomics_core_testdata(filename),
              ref_path=test_utils.genomics_core_testdata("test.fasta"),
          )
  
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 six
  from etils import epath
  from third_party.nucleus.io import sam
  from third_party.nucleus.io import tfrecord
  from third_party.nucleus.protos import reads_pb2
  from third_party.nucleus.protos import reference_pb2
  from third_party.nucleus.testing import test_utils
  from third_party.nucleus.util import ranges
label_desc: Use image node_id 1 for calling the CramReaderTests obj's underlying member method code with example usage: obj._make_reader(filename, has_embedded_ref) and returns: sam, sam