protected function _templates($customTemplate = null, $customTemplateSuffix = null)
    {
        $templates = SSViewer::get_templates_by_class(static::class, $customTemplateSuffix, __CLASS__);
        // Prefer any custom template
        if ($customTemplate) {
            // Prioritise direct template
            array_unshift($templates, $customTemplate);
        }
        return $templates;
    }