protected function populate(int $contact_person_id, &$contact_person)
 {
     if ($contact_person == null) {
         $contact_person = new activitycalendar_contact_person((int) $contact_person_id);
         $contact_person->set_organization_id($this->unmarshal($this->db->f('organization_id'), 'int'));
         $contact_person->set_group_id($this->unmarshal($this->db->f('group_id'), 'int'));
         $contact_person->set_name($this->unmarshal($this->db->f('name'), 'string'));
         $contact_person->set_phone($this->unmarshal($this->db->f('phone'), 'string'));
         $contact_person->set_email($this->unmarshal($this->db->f('email'), 'string'));
         $contact_person->set_ssn($this->unmarshal($this->db->f('ssn'), 'string'));
     }
     return $contact_person;
 }