code: public function renderHeader($content, array $options = array())
      {
          $options = $this->createResolver()
              ->setRequired(['level'])
              ->setAllowedValues(['level' => [1, 2, 3, 4, 5, 6]])
              ->resolve($options);
  
          $tag = new Tag('h' . $options['level']);
          $tag->setAttributes($options['attr']);
          $tag->setText($content);
  
          $this->getEmitter()->emit('tag', [$tag]);
  
          return $tag->render();
      }
docs: {@inheritdoc}