public void setNumberFormat(final NumberFormat FORMAT) {
        if (null == numberFormat) {
            _numberFormat = null == FORMAT ? NumberFormat.getInstance(getLocale()) : FORMAT;
            fireTileEvent(RESIZE_EVENT);
        } else {
            if (!numberFormat.isBound()) {
                numberFormat.set(FORMAT);
            }
        }
    }
Defines the number format that will be used to format the value
in the tile (NOT USED AT THE MOMENT)

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