$url = self_admin_url('update.php?action=update-selected-themes&themes=' . urlencode( join(',', $themes) ));
$url = wp_nonce_url($url, 'bulk-update-themes');
$url = self_admin_url('update.php?action=update-selected-themes&themes=' . urlencode( join(',', $themes) ));
$url = wp_nonce_url($url, 'bulk-update-themes');