public static function decode($string)
    {
        return ($string === self::NULL) ? null : strtr($string, self::$decodeMap);
    }
public static function decode($string)
    {
        return ($string === self::NULL) ? null : strtr($string, self::$decodeMap);
    }
public static function decode ( $ string ) { return ( $ string === self :: NULL ) ? null : strtr ( $ string , self :: $ decodeMap ) ; }
Decode string from server

@param $string
@return null|string
Decode string from server