{
    my $real_meth = \&LWP::UserAgent::agent;

    local *LWP::UserAgent::agent = sub {
        $_[1] = "Camel Power 3.14.15" if $_[1] =~ /XML::RSS/;
        goto &$real_meth;
    };

    $rss_object->rss_uri('http://foo/bar/index.rss');
}