if (title == null || summaryText == null || studentsNumber == null || isExtraLesson == null)
if (title == null || summaryText == null || isExtraLesson == null)
    private ISummary createSummary(String title, String summaryText, Integer studentsNumber,            Boolean isExtraLesson) {                if (title == null || summaryText == null || studentsNumber == null || isExtraLesson == null)            throw new NullPointerException();        final ISummary summary = new Summary();        summary.setTitle(title);        summary.setSummaryText(summaryText);        summary.setStudentsNumber(studentsNumber);        summary.setIsExtraLesson(isExtraLesson);        summary.setLastModifiedDate(Calendar.getInstance().getTime());        summary.setExecutionCourse(this);        return summary;    }