/**
  * Updates a program assignment activity
  *
  * @param object $assignment The data from the form
  * @return int The assignment id
  */
 function update_instance($assignment)
 {
     global $DB;
     // Add assignment instance
     $returnid = parent::update_instance($assignment);
     if ($returnid) {
         $onlinejudge = $assignment;
         $old_onlinejudge = $DB->get_record('assignment_oj', array('assignment' => $assignment->id));
         if ($old_onlinejudge) {
             $onlinejudge->id = $old_onlinejudge->id;
             $DB->update_record('assignment_oj', $onlinejudge);
         }
     }
     return $returnid;
 }