/**
  * Creates or returns an instance of this class.
  *
  * @since  0.1.0
  * @return WDS_Announcements A single instance of this class.
  */
 public static function get_instance()
 {
     if (null === self::$single_instance) {
         self::$single_instance = new self();
     }
     return self::$single_instance;
 }