code: public boolean isCancelled() {
          if (svLogger.isLoggable(Level.FINER))
              svLogger.logp(Level.FINER, CLASS_NAME, "isCancelled", toString());
          return (ivCancellationException != null); // d614969
      }
docs: This method allows clients to check the Future object to see if the
  asynchronous method was canceled before it got a chance to execute.