public function font(String $str, String $size = NULL, String $color = NULL, String $face = NULL, Array $attributes = []) : String
    {
        if( ! empty($size) )
        {
            $attributes['size'] = $size;
        }

        if( ! empty($color) )
        {
            $attributes['color'] = $color;
        }

        if( ! empty($face) )
        {
            $attributes['face'] = $face;
        }

        return $this->_multiElement('font', $str, $attributes);
    }