## both apps

$oosub = OO::SubModule->new({
  debug_cb => sub {
    my $self = shift;
    my ($str) = @_;
    goto &{_debug};
  },
});

## Any occurrence of $self->_debug("booya") within OO::SubModule really does _debug("booya") of the main app, this way
## Without getting in the call stack, right?