if( ! $fh{$fh_token}) {
        open my $fh, '>', "$fh_token.txt"
          or die "Can't write to '$fh_token.txt': $!\n";
        $fh{$fh_token} = $fh; # store filehandle
    }
    my $fh = $fh{$fh_token}; # this is the filehandle to print to