DB<159> $start=0

  DB<160> $rru = Encode::decode('utf8',$rr,sub{ $start++; return "" });

  DB<161> $sub= substr $rr,$start

  DB<162> $rru2 = Encode::decode('utf8',$sub ,Encode::FB_CROAK);

  DB<163> p $rru2 eq $rru
1
  DB<164>