anchor.diff:  
     /**
      * Requests the isolate to shut down.
  -   *
  -   * WARNING: This method is experimental and not handled on every platform yet.
      *
      * The isolate is requested to terminate itself.
      * The [priority] argument specifies when this must happen.
  
positive.code: 
    /**
     * Asks the isolate to send [response] on [responsePort] when it terminates.
     *
     * WARNING: This method is experimental and not handled on every platform yet.
     *
     * The isolate will send a `response` message on `responsePort` as the last
     * thing before it terminates. It will run no further code after the message
  
negative.code:   /**
     * Requests that uncaught errors of the isolate are sent back to [port].
     *
     * The errors are sent back as two elements lists.
     * The first element is a `String` representation of the error, usually
     * created by calling `toString` on the error.
  