public ReadOnlyDoubleProperty rangeProperty() {
        if (null == range) {
            range = new DoublePropertyBase((getMaxValue() - getMinValue())) {
                @Override protected void invalidated() { setAngleStep(getAngleRange() / get()); }
                @Override public Object getBean() { return Tile.this; }
                @Override public String getName() { return "range"; }
            };
        }
        return range;
    }
This is a private method that sets the range to the given value
which is always (maxValue - minValue).

@param RANGE
src/main/java/eu/hansolo/tilesfx/Tile.java