private static function parseDropdownChild($dropdown, $button)
    {
        if ($dropdown === false || !$dropdown instanceof Dropdown) {
            // @codingStandardsIgnoreStart
            // TODO throw exception?
            // @codingStandardsIgnoreEnd
            return;
        }

        if ($button['type'] == 'child') {
            $child = static::createDropdownItem($button['label'], $button['url'], $button['attributes'], true);
        } else {
            if ($dropdown->getChildren()) {
                $child = static::createDropdownDivider();
                $dropdown->addChild($child);
            }

            $child = static::createDropdownHeader($button['label'], $button['attributes'], true);
        }

        $dropdown->addChild($child);
    }