if (lessonSlot.getStartIndex() == hourIndex) {
if ((lessonSlot.getStartIndex() == hourIndex) && (lessonSlot.getEndIndex() == hourIndex)) { css = "period-single-slot"; } else if (lessonSlot.getStartIndex() == hourIndex) {
    private String getSlotCssClass(InfoLessonWrapper infoLessonWrapper, int hourIndex) {        String css = "period-empty-slot";        if (infoLessonWrapper != null) {            LessonSlot lessonSlot = infoLessonWrapper.getLessonSlot();            if (lessonSlot.getStartIndex() == hourIndex) {                css = "period-first-slot";            } else if (lessonSlot.getEndIndex() == hourIndex) {                css = "period-last-slot";            } else {                css = "period-middle-slot";            }        }        return css;    }