trait Singleton in Anti Spam by CleanTalk 8.4

trait Singleton {
  public static $instance;
  public function __construct() {
  }
  public function __wakeup() {
  }
  public function __clone() {
  }

  /**
   * Constructor
   * @return $this
   */
  public static function getInstance() {
    $args = func_get_args();
    if (!isset(static::$instance) || !$args) {
      static::$instance = new static();
      if (!empty($args)) {
        static::$instance
          ->init($args);
      }
      else {
        static::$instance
          ->init();
      }
    }
    return static::$instance;
  }

  /**
   * Alternative constructor
   *
   * @param null $args
   */
  protected function init($args = null) {
  }

}