* amortized since some operations can trigger a hash table resize.
 *
 * <p>Unlike {@code java.util.HashSet}, iteration is only proportional to the actual {@code size()},
 * which is optimal, and <i>not</i> the size of the internal hashtable, which could be much larger
 * than {@code size()}. Furthermore, this structure only depends on a fixed number of arrays; {@code

 * need for a distinct {@code ImmutableBiMultimap} type.
 *
 * <p><a id="iteration"></a>
 *
 * <p><b>Key-grouped iteration.</b> All view collections follow the same iteration order. In all
 * current implementations, the iteration order always keeps multiple entries with the same key
 * together. Any creation method that would customarily respect insertion order (such as {@link

	dLimbs := d.limbs[:size]
	mLimbs := m.nat.limbs[:size]

	// Each iteration of this loop computes x = 2x + b mod m, where b is a bit
	// from y. Effectively, it left-shifts x and adds y one bit at a time,
	// reducing it every time.
	//
	// To do the reduction, each iteration computes both 2x + b and 2x + b - m.
	// The next iteration (and finally the return line) will use either result
	// based on whether 2x + b overflows m.

   * cartesian product is constructed, the input lists are merely copied. Only as the resulting list
   * is iterated are the individual lists created, and these are not retained after iteration.
   *
   * @param lists the lists to choose elements from, in the order that the elements chosen from
   *     those lists should appear in the resulting lists

			switch {
			case k == nil:
				count = "no iteration variables"
			case v == nil:
				count = "one iteration variable"
			default:
				count = "two iteration variables"
			}
			check.softErrorf(&x, InvalidIterVar, "range over %s must have %s", &x, count)
		}
		key, val = k, v
	}

	// Open the for-statement block scope now, after the range clause.

	// We specifically break this out so that we can use defer here safely.
	// One option is to break this out into a new function instead, but
	// there's so much local iteration state used below that this turns out
	// to be cleaner.
	defer i.mu.Unlock()

	var oldEntry *entry[K, V]
	if n != nil {
		oldEntry = n.entry()
		if v, ok := oldEntry.lookup(key, ht.keyEqual); ok {

			switch {
			case k == nil:
				count = "no iteration variables"
			case v == nil:
				count = "one iteration variable"
			default:
				count = "two iteration variables"
			}
			check.softErrorf(&x, InvalidIterVar, "range over %s must have %s", &x, count)
		}
		key, val = k, v
	}

	// Open the for-statement block scope now, after the range clause.

          public int size() {
            return Iterators.size(iterator());
          }

          @Override
          public boolean isEmpty() {
            return !iterator().hasNext();
          }
        };
      }

      Iterator<Entry<Range<K>, V>> entryIterator() {
        if (subRange.isEmpty()) {
          return Iterators.emptyIterator();
        }
        Cut<K> cutToStart =

 * entries may be counted in {@link Cache#size}, but will never be visible to read or write
 * operations.
 *
 * <p>Certain cache configurations will result in the accrual of periodic maintenance tasks which
 * will be performed during write operations, or during occasional read operations in the absence of
 * writes. The {@link Cache#cleanUp} method of the returned cache will also perform maintenance, but

   * described in the class documentation.
   *
   * @throws NullPointerException if any of {@code elements} is null
   * @since 6.0
   */
  public static <E> ImmutableMultiset<E> copyOf(E[] elements) {
    return copyFromElements(elements);
  }

  /**
   * Returns an immutable multiset containing the given elements, in the "grouped iteration order"