public function add_image_size()
    {
        foreach($this->image_size as $id => $image)
        {
            add_image_size( $id, $image['width'], $image['height'], $image['crop'] );
        }
    }

    public static function generate_image_retina($image, $imageretina, $alt, $echo)
    {
        $srcset = '';

        if(!empty($imageretina))
        {
            $srcset = "srcset="" . esc_url($image) . " 1x, " . esc_url($imageretina) . " 2x"";
        }

        $header_logo = "<img src="" . esc_url($image) . "" " . $srcset . " alt="" . esc_attr($alt) . "">";

        if($echo) {
            echo jnews_sanitize_output($header_logo);
        } else {
            return $header_logo;
        }