public function submitContentForm() {
    $element = $this->getSession()->getPage();
    $submit = $element->findButton($this->getDrupalText('node_submit_label'));
    if (empty($submit)) {
      throw new \Exception(sprintf("No submit button at %s", $this->getSession()->getCurrentUrl()));
    }
    // Submit the form.
    $submit->click();
  }