code: public function downloadAsText(Mage_Core_Model_Config_Element $configNode)
      {
          $items = array();
          Mage::helper('sheep_debug')->xml2array($configNode, $items);
  
          $content = '';
          foreach ($items as $key => $value) {
              $content .= "$key = $value\n";
          }
  
          $this->_prepareDownloadResponse('config.txt', $content, 'text/plain');
      }
docs: Prepares response with configuration as text
  
  @param Mage_Core_Model_Config_Element $configNode