/**
  * Все студенты группы.
  * Отсортированы по ФИО
  *
  * @return CArrayList
  */
 public function getStudents()
 {
     if (is_null($this->_students)) {
         $this->_students = new CArrayList();
         foreach (CActiveRecordProvider::getWithCondition(TABLE_STUDENTS, "group_id=" . $this->getId(), "fio asc")->getItems() as $item) {
             $student = new CStudent($item);
             $this->_students->add($student->getId(), $student);
             CStaffManager::getCacheStudents()->add($student->getId(), $student);
         }
     }
     return $this->_students;
 }