public function render($src, $class = '', $id = '', array $attrs = array())
    {
        $attrs = array_merge(array(
            'frameborder' => 0,
            'content'     => null,
            'tag'         => 'iframe',
            'src'         => Str::trim($src)
        ), $attrs);

        $attrs   = $this->_cleanAttrs($attrs);
        $content = $attrs['content'];
        unset($attrs['content']);

        return Html::_('tag')->render($content, Str::trim($class), Str::trim($id), $attrs);
    }