code: protected function makeMessageFromMessagesNodeList($errorTextNodeList)
      {
          return implode(
              ' - ',
              array_map(
                  function ($item) {
                      return trim($item->nodeValue);
                  },
                  iterator_to_array($errorTextNodeList)
              )
          );
      }
docs: Convert a DomNodeList of nodes containing a (potentially partial) error message into a string.
  
  @param \DOMNodeList $errorTextNodeList
  @return string|null