public function get_2x_suffix()
 {
     if (!$this->get_size()) {
         return false;
     }
     $width = intval($this->size['width']) / 2;
     $height = intval($this->size['height']) / 2;
     return "{$width}x{$height}" . wphidpi_suffix();
 }
 function wphidpi_2x_file_name($path)
 {
     $path_bits = explode('.', $path);
     $path_2x = '';
     $length = count($path_bits);
     foreach ($path_bits as $key => $bit) {
         if ($length - 1 == $key) {
             $path_2x .= wphidpi_suffix() . '.' . $bit;
             break;
         } else {
             if ($length - 2 == $key) {
                 $path_2x .= $bit;
             } else {
                 $path_2x .= $bit . '.';
             }
         }
     }
     return $path_2x;
 }