librenms/html/pages/device/graphs/screenos.inc.php

<?php

if ($device['os'] == 'screenos' && is_file($config['rrd_dir'].'/'.$device['hostname'].'/screenos-sessions.rrd')) {
    $graph_title = 'Firewall Sessions';
    $graph_type  = 'screenos_sessions';

    include 'includes/print-device-graph.php';
}