perl -Dt -m"XML::Twig" -e ''

##</code><code>##

perl -Dx -m"XML::Twig" -e '' 2>&1 | grep print_to
# should print:
SUB XML::Twig::print_to_file = {

##</code><code>##

perl  -m"XML::Twig" -e '$twig=XML::Twig->new(); $twig->print_to_file()'