private static ExecutionSemester getBeginExecutionSemester(
final DegreeCurricularPlan dcp, final RootCourseGroup root) {
final Optional<Context> first =
root.getChildContextsSet()
.stream()
.sorted(
(o1, o2) -> o1.getBeginExecutionPeriod().compareTo(o2.getBeginExecutionPeriod()))
.findFirst();
final ExecutionSemester result =
first.isPresent()
? first.get().getBeginExecutionPeriod()
: dcp.getFirstExecutionPeriodEnrolments();
return result;
}
