}
      } else {
        super.add(elements);
      }
      return this;
    }

    private void addDeduping(E element) {
      requireNonNull(hashTable); // safe because we check for null before calling this method
      int mask = hashTable.length - 1;
      int hash = element.hashCode();
      for (int i = Hashing.smear(hash); ; i++) {
        i &= mask;
        Object previous = hashTable[i];

  ImmutableSet() {}

  public static <E> Collector<E, ?, ImmutableSet<E>> toImmutableSet() {
    return CollectCollectors.toImmutableSet();
  }

  // Casting to any type is safe because the set will never hold any elements.
  @SuppressWarnings({"unchecked"})
  public static <E> ImmutableSet<E> of() {
    return (ImmutableSet<E>) RegularImmutableSet.EMPTY;
  }

    return Math.max(
        ImmutableCollection.Builder.DEFAULT_INITIAL_CAPACITY,
        IntMath.sqrt(inputElementsIncludingAnyDuplicates, RoundingMode.CEILING));
  }

  private static final long serialVersionUID = 0xcafebabe;