code: private function implodeContent()
      {
          ksort($this->content);
          $output = '';
          foreach ($this->content as $key => $value) {
              $output .= $key . self::KV_DELIMITER . $value . self::DELIMITER;
          }
  
          return rtrim($output, self::DELIMITER);
      }
docs: Build Spayd content from parts
  
  @return string