public static function renderBlockAttrs(array $embed): string
    {
        // attributes to be rendered
        $classes = array();
        $styles = array();
        // shortcuts
        $d = &$embed['dimension'];
        // determine classes
        $classes[] = 'videoblock';
        if ($d->dynamic) {
            $classes[] = 'videoblock-dynamic';
        }
        // determine inline CSS style(s)
        // if scale model is no-scale, allow to "force dynamic"
        // by setting "dynamic" to TRUE
        if ($d->dynamic) {
            $styles[] = 'max-width:'.$d->width.'px';
        } else {
            $styles[] = 'width: '.$d->width.'px';
        }
        // render the attributes
        $class = implode(' ', $classes);
        $style = implode('; ', $styles) . (!empty($styles) ? ';' : '');
        return 'class="'.$class.'" style="'.$style.'"';
    }