public int getNumXTiles() {
        return getMaxTileX() - getMinTileX() + 1;
    }
Returns the number of tiles along the tile grid in the
horizontal direction.  getNumXTiles() is implemented in terms
of getMinTileX() and getMaxTileX() and so does not need to be
implemented by subclasses.
plugins/svg-plugin/batik-codec-fix/src/main/java/org/apache/batik/ext/awt/image/codec/util/SimpleRenderedImage.java