switch (size) {
        case 0:
          return of();
        case 1:
          /*
           * requireNonNull is safe because we ensure that the first `size` elements have been
           * populated.
           */
          return (ImmutableSet<E>) of(requireNonNull(contents[0]));
        default:
          ImmutableSet<E> result;
          if (hashTable != null && chooseTableSize(size) == hashTable.length) {