public function undo()
    {
        $returnValues = array();
        while ($undo = array_shift($this->undoParameters)) {
            $returnValues[] = $this->run($undo);
        }
        
        return $returnValues;
    }
public function undo()
    {
        $returnValues = array();
        while ($undo = array_shift($this->undoParameters)) {
            $returnValues[] = $this->run($undo);
        }
        
        return $returnValues;
    }
public function undo ( ) { $ returnValues = array ( ) ; while ( $ undo = array_shift ( $ this -> undoParameters ) ) { $ returnValues [ ] = $ this -> run ( $ undo ) ; } return $ returnValues ; }
This will execute all the undo actions in the queue. It will not clear the queue!

@return array returns the results of the undo actions, with OperationState->getKey() as the array keys
This will execute all the undo actions in the queue . It will not clear the queue!