fill_rect (Imlib2::Image)

    /*
     * Fill a rectangle at the specified coordinates.
     *
     * Examples:
     *   # fill image using context color
     *   rect = [0, 0, im.width, im.height]
     *   im.fill_rect rect
     *
     *   # fill top-left quarter of image with green
     *   color = Imlib2::Color::GREEN
     *   im.fill_rect [0, 0], [im.width / 2, im.height / 2], color
     *
     *   # fill square from 10, 10 to 30, 30 using context color
     *   im.fill_rect [10, 10, 20, 20]
     *
     */
    static VALUE image_fill_rect(int argc, VALUE *argv, VALUE self) {