I want to access get vars (or maybe post vars) in the controller of an extbase extension. I use TYPO3 7.6.12

This is the code in my controller:

```
public function showAction(\Test\MdIframe\Domain\Model\Iframe $iframe = NULL)
{
    \TYPO3\CMS\Core\Utility\DebugUtility::debug($_REQUEST);
    $args = $this->request->getArguments();
    print_r($args);

```

The debug function works, I get a filled array but `$args` remains an empty array.

Why? Has somebody an idea?