code: public function render(FormInterface $oForm, $sMessage, $bDismissable = false)
      {
          $errorHtml = sprintf($this->messageOpenFormat, $sMessage);
  
          $sMessagesArray = array();
  
          foreach ($oForm->getMessages() as $fieldName => $sMessages) {
              foreach ($sMessages as $sMessage) {
                  if ($oForm->get($fieldName)->getAttribute('id')) {
                      $sMessagesArray[] = sprintf(
                          '<a href="#%s">%s</a>',
                          $oForm->get($fieldName)->getAttribute('id'),
                          $oForm->get($fieldName)->getLabel() . ': ' . $sMessage
                      );
                  } else {
                      $sMessagesArray[] = $oForm->get($fieldName)->getLabel() . ': ' . $sMessage;
                  }
              }
          }
  
          return $this->dangerAlert(
              $errorHtml .
              implode($this->messageSeparatorString, $sMessagesArray) .
              $this->messageCloseString,
              $bDismissable
          );
      }
docs: Renders the error messages.
  @param \Zend\Form\FormInterface $oForm
  @return string