libraries/ManiaLib/Gui/Cards/Navigation/Menu.php
function addGap($gap = 4)
    {
        $item = new \ManiaLib\Gui\Elements\Spacer(1, $gap);
        $this->items[] = $item;
    }
function addGap($gap = 4)
    {
        $item = new \ManiaLib\Gui\Elements\Spacer(1, $gap);
        $this->items[] = $item;
    }
Adds a vertical gap before the next item
@param float