$fm->{ua}->add_handler("request_send",  \&pp_dump );
$fm->{ua}->add_handler("response_done", \&pp_dump );

sub pp {
    use XML::Twig;
    open my($fh), '>', \my $str;
    no warnings 'newline';
    XML::Twig->new(qw! pretty_print record !)->xparse(@_)->print( $fh );
    return $str;
}
sub pp_dump {
    my $content = $_[0]->content('');
    $_[0]->content( pp($content) );
    print $_[0]->as_string,"\n";
    return;
}