if (studentKind.getStudentType().equals(studentType)) {
if (studentKind.getStudentType() == studentType) {
    public static StudentKind readByStudentType(final StudentType studentType) {        for (final StudentKind studentKind : RootDomainObject.getInstance().getStudentKindsSet()) {            if (studentKind.getStudentType().equals(studentType)) {                return studentKind;            }        }        return null;    }