# assuming you already have $ua and have given it a cookie jar...

my $req = new HTTP::Request('GET', $url, $headers);
my $response = $ua->request($req);

# now $response is a HTTP::Response object, like the one
# in your question

if ($response->is_success) {
    print "Content-type: " . $response->headers->content_type . "\n\n";
    print $response->content;
} else {
    print "Error!!\n";
    print $response->as_string, "\n", $response->content;
}