src/Component/ContentElement/AbstractTabElement.php
protected function getIterator(): ?NavigationIterator
    {
        $parent = $this->getParent();

        if (!$parent) {
            return null;
        }

        try {
            return $this->getTabRegistry()->getIterator((string) $parent->id);
        } catch (AssertionFailedException $e) {
            return null;
        }
    }
protected function getIterator(): ?NavigationIterator
    {
        $parent = $this->getParent();

        if (!$parent) {
            return null;
        }

        try {
            return $this->getTabRegistry()->getIterator((string) $parent->id);
        } catch (AssertionFailedException $e) {
            return null;
        }
    }
Get the tab navigation iterator.

@return NavigationIterator