async getFocusedDay() {
        const focusedDay = (await Promise.all(
            weekDays.map(async weekDay => {
                const input = await this.getInput(weekDay);
                return (await input.isFocused()) ? weekDay : undefined;
            }),
        )).filter(value => value);
        return focusedDay.length ? focusedDay[0] : undefined;
    }
Returns the day that has the current focus or empty
@method