&& !teacher.getAllLegalRegimensWithoutSpecialSituations(begin,
&& !teacher.getAllLegalRegimensWithoutEndSituations(begin,
    public Teacher getTeacherByPeriod(Integer teacherNumber, Date begin, Date end) {        for (Employee employee : getWorkingEmployees(begin, end)) {            Teacher teacher = employee.getPerson().getTeacher();            if (teacher != null                    && teacher.getTeacherNumber().equals(teacherNumber)                    && !teacher.getAllLegalRegimensWithoutSpecialSituations(begin,                            end).isEmpty()) {                return teacher;            }        }        return null;    }