Can i add a widget on the same position eg "Main area - Top" more than one times?

Question

I am building a new widget and I would like to ask if there is any way programmatically to let admins to add this widget more than one times in the same position. In my case at the position "Main area -Top". How can I achieve this behavior?

I checked the file admin-widgets.php and found this part of code:

$region = $regioncodes[substr($place, 0, 1)];

    $widgetallowed = method_exists($module, 'allow_region') && $module->allow_region($region);

    if ($widgetallowed) {
        foreach ($widgets as $widget) {
            if ($widget['place'] == $place && $widget['title'] == $editwidget['title'] && $widget['widgetid'] !== @$editwidget['widgetid'])
                $widgetallowed = false; // don't allow two instances of same widget in same place
        }
    }

But how can I override this code in my custom widget file as I dont want to modify core files?? I need the $widgetallowed var to be true. -> $widgetallowed = true;