public BooleanProperty strokeWithGradientProperty() {
        if (null == strokeWithGradient) {
            strokeWithGradient = new BooleanPropertyBase(_strokeWithGradient) {
                @Override protected void invalidated() { fireTileEvent(REDRAW_EVENT); }
                @Override public Object getBean() { return Tile.this; }
                @Override public String getName() { return "strokeWithGradient"; }
            };
        }
        return  strokeWithGradient;
    }
Defines the usage of a gradient defined by gradientStops to stroke the line
in the SparklineTileSkin
@param STROKE_WITH_GRADIENT
src/main/java/eu/hansolo/tilesfx/Tile.java