private function getColumnHeaders(&$results) {
    $html = '<h3>Column Headers</h3><pre>';

    $headers = $results->getColumnHeaders();
    foreach ($headers as $header) {
      $html .= <<<HTML

Column Name = {$header->getName()}
Column Type = {$header->getColumnType()}
Data Type   = {$header->getDataType()}

HTML;
    }

    $html .= '</pre>';
    return $html;
  }