switch (elements.length) {
      case 0:
        return of();
      case 1:
        return of(elements[0]);
      default:
        return construct(elements.length, elements.clone());
    }
  }

  ImmutableSet() {}

  /** Returns {@code true} if the {@code hashCode()} method runs quickly. */
  boolean isHashCodeFast() {
    return false;
  }

  @Override

      super.putAll(entries);
      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
      super.putAll(key, values);
      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> putAll(K key, V... values) {
      super.putAll(key, values);
      return this;
    }

    public int compareTo(ClassWithTerribleHashCode that) {
      return Integer.compare(this.value, that.value);
    }

    @Override
    public boolean equals(@Nullable Object x) {
      return x instanceof ClassWithTerribleHashCode
          && ((ClassWithTerribleHashCode) x).value == value;
    }

    @Override
    public int hashCode() {
      return 23;
    }

    @Override
    public String toString() {