code: def test_str_and_repr(self):
      self.assertIsInstance(str(self.in_mem), six.string_types)
      self.assertIsInstance(repr(self.in_mem), six.string_types)
  
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
  import six
  from third_party.nucleus.io import fasta
  from third_party.nucleus.io.python import reference
  from third_party.nucleus.testing import test_utils
  from third_party.nucleus.util import ranges
label_desc: Use image node_id 10 for calling the InMemoryFastaReaderTests obj's underlying member method code with example usage: obj.test_str_and_repr() without return types