public static function GetByExtension( string $extension ) : string
   {

      $normalizedExtension = \strtolower( \ltrim( $extension, '.' ) );

      if ( isset( static::$mimeTypes[ $normalizedExtension ] ) )
      {
         return static::$mimeTypes[ $normalizedExtension ];
      }

      return 'application/octet-stream';

   }