code: def test_no_details(self):
      e = errors.UnauthenticatedError(challenge="Digest")
      expected_msg = "Unauthenticated"
      self.assertEqual(str(e), expected_msg)
  
imports: from tensorboard import errors
  from tensorboard import test
label_desc: Use image node_id 1 for calling the UnauthenticatedErrorTest obj's underlying member method code with example usage: obj.test_no_details() without return types