ew PrefixedMessageTest();
      var featureString = `${featuresPrefix}${feature}`;
      prefixedMessage.onMessage(t.step_func_done((data, e) => {
        e.source.close();
        assert_equals(data.height, 405, `"${featureString} value after first non-digit will be ignored"`);
      }));
      var win = window.open(prefixedMessage.url(windowURL) + "&expected_innerHeight=405", '', featureString);
    }, `features "${feature}" should set "height=405"`);
  });

}

</script>
