code: public static Calendar endOfWeek(Calendar calendar, boolean isSundayAsLastDay) {
  		if(isSundayAsLastDay) {
  			calendar.setFirstDayOfWeek(Calendar.MONDAY);
  		}
  		return ceiling(calendar, DateField.WEEK_OF_MONTH);
  	}
docs: 获取某周的结束时间
  
  @param calendar 日期 {@link Calendar}
  @param isSundayAsLastDay 是否周日做为一周的最后一天（false表示周六做为最后一天）
  @return {@link Calendar}
  @since 3.1.2