* read operations anyway:
     *
     * - All (unsynchronized) read operations must first read the "count" field, and should not
     * look at table entries if it is 0.
     *
     * - All (synchronized) write operations should write to the "count" field after structurally
     * changing any bin. The operations must not take any action that could even momentarily

   * Returns an iterator over the merged contents of all given {@code iterators}, traversing every
   * element of the input iterators. Equivalent entries will not be de-duplicated.
   *
   * <p>Callers must ensure that the source {@code iterators} are in non-descending order as this
   * method does not sort its input.
   *
   * <p>For any equivalent elements across all {@code iterators}, it is undefined which element is
   * returned first.

a single byte in the string.
</li>

<li>
The iteration order over maps is not specified
and is not guaranteed to be the same from one iteration to the next.
If a map entry that has not yet been reached is removed during iteration,
the corresponding iteration value will not be produced. If a map entry is
created during iteration, that entry may be produced during the iteration or

a single byte in the string.
</li>

<li>
The iteration order over maps is not specified
and is not guaranteed to be the same from one iteration to the next.
If a map entry that has not yet been reached is removed during iteration,
the corresponding iteration value will not be produced. If a map entry is
created during iteration, that entry may be produced during the iteration or

     * read operations anyway:
     *
     * - All (unsynchronized) read operations must first read the "count" field, and should not
     * look at table entries if it is 0.
     *
     * - All (synchronized) write operations should write to the "count" field after structurally
     * changing any bin. The operations must not take any action that could even momentarily

  /**
   * Returns the next element in the iteration, without advancing the iteration.
   *
   * <p>Calls to {@code peek()} should not change the state of the iteration, except that it
   * <i>may</i> prevent removal of the most recent element via {@link #remove()}.
   *
   * @throws NoSuchElementException if the iteration has no more elements according to {@link
   *     #hasNext()}
   */

  /**
   * Returns the next element in the iteration, without advancing the iteration.
   *
   * <p>Calls to {@code peek()} should not change the state of the iteration, except that it
   * <i>may</i> prevent removal of the most recent element via {@link #remove()}.
   *
   * @throws NoSuchElementException if the iteration has no more elements according to {@link
   *     #hasNext()}
   */

     * read operations anyway:
     *
     * - All (unsynchronized) read operations must first read the "count" field, and should not look
     * at table entries if it is 0.
     *
     * - All (synchronized) write operations should write to the "count" field after structurally
     * changing any bin. The operations must not take any action that could even momentarily cause a

 * }</pre>
 *
 * ... the iteration order for {@link #keys()} is {@code [key1, key2, key1]}, and similarly for
 * {@link #entries()}. Unlike {@link LinkedHashMultimap}, the iteration order is kept consistent
 * between keys, entries and values. For example, calling:
 *
 * <pre>{@code
 * multimap.remove(key1, foo);
 * }</pre>
 *
 * <p>changes the entries iteration order to {@code [key2=bar, key1=baz]} and the key iteration

   * {@code factory}, and the multimap contents are all serializable.
   *
   * <p>The multimap is not threadsafe when any concurrent operations update the multimap, even if
   * {@code map} and the instances generated by {@code factory} are. Concurrent read operations will
   * work correctly. To allow concurrent update operations, wrap the multimap with a call to {@link
   * #synchronizedMultimap}.
   *