require Tk::GraphItems

Tk::GraphItems->TextBox(args)

require Tk::GraphItems::TextBox;

...

#und dann 
Tk::GraphItems::TextBox->new(@args);

use strict;
use warnings;
use Tk;
use Tk::GraphItems;
use Tk::GraphItems::TextBox;

my $mw = tkinit;


my $c = $mw->Canvas->pack;

my $tb = Tk::GraphItems::TextBox->new(canvas => $c,
                        x => 10,
                        y => 20,
                        text => 'test');
MainLoop;