$HTTP::Request::Common::DYNAMIC_FILE_UPLOAD = 1;
my $req = make_http_request();
my $gen = $req->content();
die unless ref($gen) eq "CODE";

$req->content(
	sub {
		my $chunk = &$gen();
		print "." x (length($chunk)/1024) if defined $chunk;
		return $chunk;
	}
);
my $res = $ua->request($req);