}

    /**
     * {@inheritDoc}
     *
     * @since 10.0
     */
    @Override
    public void addListener(Runnable listener, Executor exec) {
      executionList.add(listener, exec);
    }

    /**
     * Subclasses should invoke this method to set the result of the computation to {@code value}.

    }

    /**
     * {@inheritDoc}
     *
     * @since 10.0
     */
    @Override
    public void addListener(Runnable listener, Executor exec) {
      executionList.add(listener, exec);
    }

    /**
     * Subclasses should invoke this method to set the result of the computation to {@code value}.