}
    }
    Arrays.fill(elements, uniques, n, null);
    if (uniques == 1) {
      // There is only one element or elements are all duplicates
      @SuppressWarnings("unchecked") // we are careful to only pass in E
      // requireNonNull is safe because the first `uniques` elements are non-null.
      E element = (E) requireNonNull(elements[0]);
      return new SingletonImmutableSet<E>(element);