final IGroupEnrolmentStrategyFactory enrolmentGroupPolicyStrategyFactory = GroupEnrolmentStrategyFactory.getInstance();
final IGroupEnrolmentStrategy strategy = enrolmentGroupPolicyStrategyFactory.getGroupEnrolmentStrategyInstance(grouping);
if (grouping.getStudentAttend(studentUsername) == null) {
throw new NoChangeMadeServiceException();
}
Shift shift = null;
if (shiftID != null) {
shift = FenixFramework.getDomainObject(shiftID);
}