I'm using WWW::Mechanize to check if some files exist on a webserver.
I don't want to download the whole file, only some 10KB of it
I cannot use $mech->max_size because i think the server does not support the range header and thus responds with a "403 Forbidden".
So here is the code I try to run:

my $mech = new WWW::Mechanize(
        max_redirect => 20,
        autocheck => 1,
        onerror => \&onFetchError,
        onwarn => \&onFetchWarn
);

# i cannot use max_size because i get a 403
# $mech->max_size("10240");
# so here is what i came up with:
$mech->get($myUrl,":content_cb"=> \&myCallback);

sub myCallback{
    my ($data, $response, $protocol) = @_;
    my $totalData .= $data;
    if( (length($totalData ) / 1024) > 10 ){
        #I want to stop the transfer now
        #but it's not working this way...
        $mech = undef;
    }
}
[download]

Do you have any ideea how can i do this ? Or maybe other better solutions ?
Thanks