final ISuportePersistente persistentSupport = PersistenceSupportFactory .getDefaultPersistenceSupport(); final IPersistentStudent persistentStudent = persistentSupport.getIPersistentStudent();  final IStudent student = persistentStudent.readByUsername(username); final List<IStudent> groupingStudents = getGroupingStudents(grouping);  return groupingStudents.contains(student);
final IAttends attend = grouping.getStudentAttend(username); return attend != null;
    public boolean checkStudentInGrouping(IGrouping grouping, String username)            throws ExcepcaoPersistencia {        final ISuportePersistente persistentSupport = PersistenceSupportFactory                .getDefaultPersistenceSupport();        final IPersistentStudent persistentStudent = persistentSupport.getIPersistentStudent();        final IStudent student = persistentStudent.readByUsername(username);        final List<IStudent> groupingStudents = getGroupingStudents(grouping);        return groupingStudents.contains(student);    }