code: public static void invokeMethodTask (String name, Object source, TaskObserver observer)
      {
          // create a method task instance to invoke the named method and
          // then run that through the normal task invocation mechanism
          invokeTask(name, new MethodTask(name, source), observer);
      }
docs: Invokes the method with the specified name on the supplied source
  object as if it were a task. The observer is notified when the
  method has completed and returned its result or if it fails. The
  named method must have a signature the same as the
  <code>invoke</code> method of the <code>Task</code> interface.
  Aborting tasks run in this way is not supported.