public static function get_hierarchy()
 {
     $city_counsil_departments = array();
     $city_counsil_dep = $GLOBALS['phpgw']->locations->get_subs_from_pattern('rental', city_counsil_dep::$pattern);
     foreach ($city_counsil_dep as $department) {
         $name = $department['name'];
         $dep = new city_counsil_dep($department['location_id'], $name, $department['descr']);
         $city_counsil_departments[city_counsil_dep::get_identifier_from_name($dep->get_name())] = $dep;
     }
     $result_units = $GLOBALS['phpgw']->locations->get_subs_from_pattern('rental', result_unit::$pattern);
     foreach ($result_units as $result_unit) {
         $unit = new result_unit($result_unit['location_id'], $result_unit['name'], $result_unit['descr']);
         $city_counsil_dep_identifier = city_counsil_dep::get_identifier_from_name($unit->get_name());
         $dep = $city_counsil_departments[$city_counsil_dep_identifier];
         $dep->add_result_unit($unit);
     }
     return $city_counsil_departments;
 }
 public function add_result_unit(result_unit $result_unit)
 {
     $this->result_units[result_unit::get_identifier_from_name($result_unit->get_name())] = $result_unit;
 }