properties.add(IntProperty('maxLines', maxLines, defaultValue: 1));

    // Specify the unit as otherwise it would be unclear that time is in
    // milliseconds.
    properties.add(IntProperty('duration', duration.inMilliseconds, unit: 'ms'));

    // Tooltip is used instead of unit for this case as a unit should be a
    // terse description appropriate to display directly after a number
    // without a space.
    properties.add(DoubleProperty(
      'device pixel ratio',
      ui.window.devicePixelRatio