public MenuScheme maskEmpty(int lines) {
        for (int i = 0; i < lines; i++) {
            this.maskRows.add(EMPTY_MASK);
            this.schemeRows.add(EMPTY_SCHEME);
        }
        return this;
    }
Helps to populate a menu with border items
helper/src/main/java/me/lucko/helper/menu/scheme/MenuScheme.java