public IAttends getStudentAttend(String studentUsername) {
public IAttends getStudentAttend(IStudent student) {
    public IAttends getStudentAttend(String studentUsername) {        for (final IAttends attend : this.getAttends()) {            if (attend.getAluno().getPerson().getUsername().equals(studentUsername)) {                return attend;            }        }        return null;    }