public static BillNames fromByte(byte b) {
        switch (b) {
            case 1:
                return Bill1;
            case 2:
                return Bill2;
            case 3:
                return Bill3;
            case 4:
                return Bill4;
            case 5:
                return Bill5;
            case 6:
                return Bill6;
            case 7:
                return Bill7;

            default:
                return Invalid;
        }
    }