src/View/Tab/TabRegistry.php
public function getIterator(string $elementId): NavigationIterator
    {
        if (!isset($this->iterators[$elementId])) {
            $this->iterators[$elementId] = new NavigationIterator($this->getNavigation($elementId));
        }

        return $this->iterators[$elementId];
    }
public function getIterator(string $elementId): NavigationIterator
    {
        if (!isset($this->iterators[$elementId])) {
            $this->iterators[$elementId] = new NavigationIterator($this->getNavigation($elementId));
        }

        return $this->iterators[$elementId];
    }
Get the iterator.

@param string $elementId The element id.

@return NavigationIterator

@throws \Assert\AssertionFailedException When an invalid element is given.