*
   * <ul>
   *   <li>Any {@link ExecutionException} has its <i>cause</i> wrapped in an {@link
   *       UncheckedExecutionException} (if the cause is an {@code Exception}) or {@link
   *       ExecutionError} (if the cause is an {@code Error}).
   *   <li>Any {@link InterruptedException} causes a retry of the {@code get} call. The interrupt is
   *       restored before {@code getUnchecked} returns.