class position {
    get name() {
        throw "This is abstract getter.";
    }

    get top_css() {
        return "auto";
    }

    get bottom_css() {
        return "auto";
    }

    get left_css() {
        return "auto";
    }

    get right_css() {
        return "auto";
    }
}

class place_top extends position {
    get name() {
        return "top";
    }

    get top_css() {
        return "0px";
    }
}

class place_bottom extends position {
    get name() {
        return "bottom";
    }

    get bottom_css() {
        return "0px";
    }   
}

class place_left extends position {
    get name() {
        return "left";
    }

    get left_css() {
        return "0px";
    }
}

class place_right extends position {
    get name() {
        return "right";
    }

    get right_css() {
        return "0px";
    }
}
export { position, place_top, place_bottom, place_left, place_right };