for (Registration registration : RootDomainObject.getInstance().getStudents()) {
for (Registration registration : RootDomainObject.getInstance().getRegistrations()) {
	public static List<Registration> readStudentsByDegreeType(DegreeType degreeType) {		List<Registration> students = new ArrayList();		for (Registration registration : RootDomainObject.getInstance().getStudents()) {			if (registration.getDegreeType().equals(degreeType)) {				students.add(registration);			}		}		return students;	}