anchor.diff:     * If the same port has been passed via [addErrorListener] more than once,
      * only one call to `removeErrorListener` is needed to stop it from receiving
      * unaught errors.
  -   *
  -   * Closing the receive port at the end of the send port will not stop the
  -   * isolate from sending uncaught errors, they are just going to be lost.
      *
      * Uncaught errors message may still be sent by the isolate
      * until this request is received and processed.
  
positive.code:    * This call requires the [terminateCapability] for the isolate.
     * If the capability is absent or incorrect, no change is made.
     *
     * Since isolates run concurrently, it's possible for it to exit due to an
     * error before errors are set non-fatal.
     * To avoid this, either use the corresponding parameter to the spawn
     * function, or start the isolate paused, set errors non-fatal and
     * then resume the isolate.
  
negative.code:   external void addOnExitListener(SendPort responsePort, {Object response});
  
    /**
     * Stops listening for exit messages from the isolate.
     *
     * Requests for the isolate to not send exit messages on [responsePort].
     * If the isolate isn't expecting to send exit messages on [responsePort],
  