}
	private void checkIfReachedAttendsLimit() {		if (readAttendsInCurrentExecutionPeriod().size() >= MAXIMUM_STUDENT_ATTENDS_PER_EXECUTION_PERIOD) {			throw new DomainException("error.student.reached.attends.limit", String					.valueOf(MAXIMUM_STUDENT_ATTENDS_PER_EXECUTION_PERIOD));		}	}