public function addMessage(Doozr_Form_Service_Component_Message $message)
    {
        $index               = $this->addChild($message);
        $this->index[$index] = self::MESSAGE;

        (!isset($this->indexReverse[self::MESSAGE])) ? $this->indexReverse[self::MESSAGE] = [] : null;
        $this->indexReverse[self::MESSAGE][]                                              = $index;

        return $index;
    }