public function getRootParagraph()
    {
        if ( $this->proxyBase->rootId && (
                null === $this->rootParagraph ||
                $this->rootParagraph->id != $this->proxyBase->rootId
            ) )
        {
            $this->rootParagraph = $this->getMapper()
                                        ->find( $this->proxyBase->rootId );
        }

        return $this->rootParagraph;
    }