use XML::Twig;
my $t = XML::Twig->new( 
    twig_roots => {
        Doc => \&mutilate_doc,
    },
); 

$t->parse(\*DATA);

sub mutilate_doc {
    my( $t, $doc)= @_;
    $doc->print;
    print "\n",'x'x69,"\n";
}

__END__
<Stream>
<Doc>
<foo>hey man</foo>
</Doc>
<Doc>
<bar>hey man, how's it goin'?</bar>
</Doc>
<Doc>
<baz>pretty right on.</baz>
</Doc>
</Stream>