text: <?php
  
  /*
   * This file is part of SwiftMailer.
   * (c) 2004-2009 Chris Corbyn
   *
   * For the full copyright and license information, please view the LICENSE
   * file that was distributed with this source code.
   */
  
  /**
   * Message ID generator.
   */
  interface Swift_IdGenerator
  {
      /**
       * Returns a globally unique string to use for Message-ID or Content-ID.
       *
       * @return string
       */
      public function generateId();
  }
  