$ perl -E 'use Tk; my $mw = MainWindow::->new(); say $mw->Canvas'
Tk::Canvas=HASH(0x8003cb500)

##</code><code>##

$ perl -E 'use Tk; my $mw = MainWindow::->new(); say $mw->Listbox'
Tk::Listbox=HASH(0x8006859e8)

$ perl -E 'use Tk; my $mw = MainWindow::->new(); say $mw->Scrolled("Listbox")'
Tk::Frame=HASH(0x800647820)

##</code><code>##

my $scrl_listbox = $mw->Scrolled("Listbox", ...);