src/Knp/Menu/Twig/MenuExtension.php
public function pathAsString(ItemInterface $menu, $separator = ' > ')
    {
        if (null === $this->menuManipulator) {
            throw new \BadMethodCallException('The menu manipulator must be set to get the breadcrumbs array');
        }

        return $this->menuManipulator->getPathAsString($menu, $separator);
    }
public function pathAsString(ItemInterface $menu, $separator = ' > ')
    {
        if (null === $this->menuManipulator) {
            throw new \BadMethodCallException('The menu manipulator must be set to get the breadcrumbs array');
        }

        return $this->menuManipulator->getPathAsString($menu, $separator);
    }
A string representation of this menu item

e.g. Top Level > Second Level > This menu

@param ItemInterface $item
@param string        $separator

@return string