}

  @CanIgnoreReturnValue
  CacheBuilderFactory withKeyStrengths(Set<Strength> keyStrengths) {
    this.keyStrengths = new LinkedHashSet<>(keyStrengths);
    Preconditions.checkArgument(!this.keyStrengths.contains(Strength.SOFT));
    return this;
  }

  @CanIgnoreReturnValue
  CacheBuilderFactory withValueStrengths(Set<Strength> valueStrengths) {
    this.valueStrengths = new LinkedHashSet<>(valueStrengths);
    return this;
  }

  * More expressive node affinity syntax, and support for “soft” node affinity.
Node selectors (to constrain pods to schedule on a subset of nodes) now support
the operators {<code>In, NotIn, Exists, DoesNotExist, Gt, Lt</code>}  instead of just conjunction of exact match on node label values. In
addition, we’ve introduced a new “soft” kind of node selector that is just a

    return warmUp(cache, WARMUP_MIN, WARMUP_MAX);
  }

  /**
   * Returns the entries that were added to the map, so they won't fall out of a map with weak or
   * soft references until the caller drops the reference to the returned entries.
   */
  private List<Entry<Object, Object>> warmUp(
      LoadingCache<Object, Object> cache, int minimum, int maximum) {

    return warmUp(cache, WARMUP_MIN, WARMUP_MAX);
  }

  /**
   * Returns the entries that were added to the map, so they won't fall out of a map with weak or
   * soft references until the caller drops the reference to the returned entries.
   */
  private List<Entry<Object, Object>> warmUp(
      LoadingCache<Object, Object> cache, int minimum, int maximum) {

   * demand.
   *
   * <p><b>Warning:</b> in most circumstances it is better to set a per-cache {@linkplain
   * #maximumSize(long) maximum size} instead of using soft references. You should only use this
   * method if you are well familiar with the practical consequences of soft references.
   *
   * <p><b>Note:</b> when this method is used, the resulting cache will use identity ({@code ==})
   * comparison to determine equality of values.

     * value. This could save ~8 bytes per entry.
     */

    STRONG {
      @Override
      Equivalence<Object> defaultEquivalence() {
        return Equivalence.equals();
      }
    },

    SOFT {
      @Override
      Equivalence<Object> defaultEquivalence() {
        return Equivalence.identity();
      }
    },

    WEAK {
      @Override
      Equivalence<Object> defaultEquivalence() {

   *
   * <p>Note: the table assumes complete ownership over of {@code backingMap} and the maps returned
   * by {@code factory}. Those objects should not be manually updated and they should not use soft,
   * weak, or phantom references.
   *
   * @param backingMap place to store the mapping from each row key to its corresponding column key
   *     / value map

    if (threadStarted) {
      return;
    }

    Reference<?> reference;
    while ((reference = queue.poll()) != null) {
      /*
       * This is for the benefit of phantom references. Weak and soft references will have already
       * been cleared by this point.
       */
      reference.clear();
      try {
        ((FinalizableReference) reference).finalizeReferent();
      } catch (Throwable t) {

   *
   * <p>Note: the multimap assumes complete ownership over of {@code map} and the collections
   * returned by {@code factory}. Those objects should not be manually updated and they should not
   * 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

   * To maintain this code, make a change for the strong reference type. Then, cut and paste, and
   * replace "Strong" with "Soft" or "Weak" within the pasted text. The primary difference is that
   * strong entries store the key reference directly while soft and weak entries delegate to their
   * respective superclasses.
   */

  /** Used for strongly-referenced keys. */