public void createCourseReport(String report) {
public ICourseReport createCourseReport(String report) {
    public void createCourseReport(String report) {        if (report == null)            throw new NullPointerException();        final ICourseReport courseReport = new CourseReport();        courseReport.setReport(report);        courseReport.setLastModificationDate(Calendar.getInstance().getTime());        courseReport.setExecutionCourse(this);    }