code: static <T> TableIterator<T> empty() {
          return new TableIterator<>(
                  () -> CompletableFuture.completedFuture(null),
                  ignored -> CompletableFuture.completedFuture(null),
                  new ArrayDeque<>(),
                  ForkJoinPool.commonPool());
      }
docs: Creates a new {@link TableIterator} that contains no elements.
  
  @param <T> Type of elements returned at each iteration.
  @return A new instance of the {@link TableIterator.Builder} class.