self.assertIsNone(rfc2544_resource_helper._tolerance_high)
self.assertEqual(rfc2544_resource_helper.tolerance_high, 0.15)
self.assertEqual(rfc2544_resource_helper._tolerance_high, 0.15)
self.assertIsNone(rfc2544_resource_helper._tolerance_high)
self.assertEqual(rfc2544_resource_helper.tolerance_high, 0.15)
self.assertEqual(rfc2544_resource_helper._tolerance_high, 0.15)