public ObjectProperty<CountryGroup> countryGroupProperty() {
        if (null == countryGroup) {
            countryGroup = new ObjectPropertyBase<CountryGroup>(_countryGroup) {
                @Override protected void invalidated() { fireTileEvent(RECALC_EVENT); }
                @Override public Object getBean() { return Tile.this; }
                @Override public String getName() { return "countryGroup"; }
            };
            _countryGroup = null;
        }
        return countryGroup;
    }
Defines the Locale that will be used to visualize the country
in the CountryTileSkin
@param COUNTRY
src/main/java/eu/hansolo/tilesfx/Tile.java