protected static function filterEncoding(string $encoding): string
    {
        static $encoding_list;
        if (null === $encoding_list) {
            $list = mb_list_encodings();
            $encoding_list = array_combine(array_map('strtolower', $list), $list);
        }

        $key = strtolower($encoding);
        if (isset($encoding_list[$key])) {
            return $encoding_list[$key];
        }

        throw new OutOfRangeException(sprintf('The submitted charset %s is not supported by the mbstring extension', $encoding));
    }
protected static function filterEncoding(string $encoding): string
    {
        static $encoding_list;
        if (null === $encoding_list) {
            $list = mb_list_encodings();
            $encoding_list = array_combine(array_map('strtolower', $list), $list);
        }

        $key = strtolower($encoding);
        if (isset($encoding_list[$key])) {
            return $encoding_list[$key];
        }

        throw new OutOfRangeException(sprintf('The submitted charset %s is not supported by the mbstring extension', $encoding));
    }
protected static function filterEncoding ( string $ encoding ) : string { static $ encoding_list ; if ( null === $ encoding_list ) { $ list = mb_list_encodings ( ) ; $ encoding_list = array_combine ( array_map ( 'strtolower' , $ list ) , $ list ) ; } $ key = strtolower ( $ encoding ) ; if ( isset ( $ encoding_list [ $ key ] ) ) { return $ encoding_list [ $ key ] ; } throw new OutOfRangeException ( sprintf ( 'The submitted charset %s is not supported by the mbstring extension' , $ encoding ) ) ; }
Filter encoding charset.

@throws OutOfRangeException if the charset is malformed or unsupported
Filter encoding charset .