anchor.diff:     * anywhere else, so the capabilities should come from the same isolate as
      * the control port.
      *
  -   * If all the available capabilities are included,
  -   * there is no reason to create a new object,
  -   * since the behavior is defined entirely
  -   * by the control port and capabilities.
  +   * Can also be used to create an [Isolate] object from a control port, and
  +   * any available capabilities, that have been sent through a [SendPort].
  +   *
  +   * Example:
  +   * ```dart
  +   * Isolate isolate = findSomeIsolate();
  +   * Isolate restrictedIsolate = new Isolate(isolate.controlPort);
  +   * untrustedCode(restrictedIsolate);
  +   * ```
  +   * This example creates a new `Isolate` object that cannot be used to
  +   * pause or terminate the isolate. All the untrusted code can do is to
  +   * inspect the isolate and see uncaught errors or when it terminates.
      */
     Isolate(this.controlPort, {this.pauseCapability,
                                this.terminateCapability});
  
positive.code:    * event loop and shut down the isolate.
     *
     * This call requires the [terminateCapability] for the isolate.
     * If the capability is not correct, 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.
  
negative.code:  * for example by pausing the isolate or by getting events when the isolate
   * has an uncaught error.
   *
   * The [controlPort] identifies and gives access to controlling the isolate,
   * and the [pauseCapability] and [terminateCapability] guard access
   * to some control operations.
   * For example, calling [pause] on an `Isolate` object created without a
   * [pauseCapability], has no effect.
   *
   * The `Isolate` object provided by a spawn operation will have the
   * control port and capabilities needed to control the isolate.
   * New isolate objects can be created without some of these capabilities
   * if necessary, using the [Isolate.Isolate] constructor.
   *
   * An `Isolate` object cannot be sent over a `SendPort`, but the control port
   * and capabilities can be sent, and can be used to create a new functioning
  