my $utf8_decodable_regex =
       qr/[\xC0-\xDF][\x80-\xBF]    | # 2 bytes unicode char
       [\xE0-\xEF][\x80-\xBF]{2} | # 3 bytes unicode char
       [\xF0-\xFF][\x80-\xBF]{3}/x;


            $testStr=~ s/($utf8_decodable_regex)/decode('UTF-8',$1,Encode::FB_CROAK | Encode::LEAVE_SRC)/gex;
            #$testStr = decode('utf-8',$testStr) if $testStr=~/$utf8_decodable_regex/;