private void addExecutionCourses(final CourseGroup courseGroup, final Collection<ExecutionCourseView> executionCourseViews,
final ExecutionSemester... executionPeriods) {
for (final Context context : courseGroup.getChildContextsSet()) {
for (final ExecutionSemester executionSemester : executionPeriods) {
if (context.isValid(executionSemester)) {
final DegreeModule degreeModule = context.getChildDegreeModule();
if (degreeModule.isLeaf()) {
final CurricularCourse curricularCourse = (CurricularCourse) degreeModule;
for (final ExecutionCourse executionCourse : curricularCourse.getAssociatedExecutionCoursesSet()) {
if (executionCourse.getExecutionPeriod() == executionSemester) {
final Integer curricularYear = context.getCurricularYear();
executionCourseViews.add(constructExecutionCourseView(executionCourse, curricularYear));