XML Site Map - Custom

Hello,

Is there anyway to combine both perch_pages_navigation and perch_blog_custom array together to achieve both to output at the same time? The below is giving me an error.

    <?php
    header('Content-type: application/xml');
    include('perch/runtime.php');
    perch_pages_navigation (array(
        'template'=>'sitemap.html',
        'flat'=>true

    perch_blog_custom(array(
    'template' => 'sitemap.html',
    'flat'=>true
));
?>