}

  /**
   * Returns the empty multimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting is safe because the multimap will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableSetMultimap<K, V> of() {
    return (ImmutableSetMultimap<K, V>) EmptyImmutableSetMultimap.INSTANCE;
  }

    HashSet<E> set = newHashSet();
    Iterators.addAll(set, elements);
    return set;
  }

  /**
   * Returns a new hash set using the smallest initial table size that can hold {@code expectedSize}
   * elements without resizing. Note that this is not what {@link HashSet#HashSet(int)} does, but it
   * is what most users want and expect it to do.
   *

   * use soft, weak, or phantom references.
   *
   * @param map place to store the mapping from each key to its corresponding values
   * @param factory supplier of new, empty collections that will each hold all values for a given
   *     key
   * @throws IllegalArgumentException if {@code map} is not empty
   */
  public static <K extends @Nullable Object, V extends @Nullable Object> Multimap<K, V> newMultimap(

  }

  /**
   * Returns the empty bimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting to any type is safe because the set will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableBiMap<K, V> of() {
    return (ImmutableBiMap<K, V>) RegularImmutableBiMap.EMPTY;
  }

      Map<? extends K, ? extends V> map) {
    return new HashMap<>(map);
  }

  /**
   * Creates a {@code HashMap} instance, with a high enough "initial capacity" that it <i>should</i>
   * hold {@code expectedSize} elements without growth. This behavior cannot be broadly guaranteed,
   * but it is observed to be true for OpenJDK 1.7. It also can't be guaranteed that the method

  }

  /**
   * Returns the empty multimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting is safe because the multimap will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableListMultimap<K, V> of() {
    return (ImmutableListMultimap<K, V>) EmptyImmutableListMultimap.INSTANCE;
  }

  /**
   * Returns an array size suitable for the backing array of a hash table that uses open addressing
   * with linear probing in its implementation. The returned size is the smallest power of two that
   * can hold setSize elements with the desired load factor. Always returns at least setSize + 2.
   */
  @VisibleForTesting
  static int chooseTableSize(int setSize) {
    setSize = Math.max(setSize, 2);

   * code.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting to any type is safe because the list will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <E> ImmutableList<E> of() {
    return (ImmutableList<E>) EMPTY;
  }

  /**