*
 * <p>A step can be the input to at most one derived step. Once you transform its value, catch its
 * exception, or combine it with others, you cannot do anything else with it, including declare it
 * to be the last step of the pipeline.
 *
 * <h4>Transforming</h4>
 *
 * To derive the next step by asynchronously applying a function to an input step's value, call

   * hash functions. This is critical when the concurrent hash map uses power-of-two length hash
   * tables, that otherwise encounter collisions for hash codes that do not differ in lower or upper
   * bits.
   *
   * @param h hash code
   */
  static int rehash(int h) {
    // Spread bits to regularize both segment and index locations,

      return ImmutableMap.of();
    }
    Entry<K, ? extends V> entry1 = entryItr.next();
    K key1 = entry1.getKey();
    V value1 = entry1.getValue();
    checkEntryNotNull(key1, value1);
    // Do something that works for j2cl, where we can't call getDeclaredClass():
    EnumMap<K, V> enumMap = new EnumMap<>(singletonMap(key1, value1));
    while (entryItr.hasNext()) {
      Entry<K, ? extends V> entry = entryItr.next();

   * hash functions. This is critical when the concurrent hash map uses power-of-two length hash
   * tables, that otherwise encounter collisions for hash codes that do not differ in lower or upper
   * bits.
   *
   * @param h hash code
   */
  static int rehash(int h) {
    // Spread bits to regularize both segment and index locations,