@CanIgnoreReturnValue
  public boolean cancel(boolean mayInterruptIfRunning) {
    logger.get().log(FINER, "cancelling {0}", this);
    boolean cancelled = future.cancel(mayInterruptIfRunning);
    if (cancelled) {
      close();
    }
    return cancelled;
  }

  private void close() {
    logger.get().log(FINER, "closing {0}", this);
    closeables.close();
  }