.put("concurrencyLevel", new ConcurrencyLevelParser())
          .put("weakKeys", new KeyStrengthParser(Strength.WEAK))
          .put("softValues", new ValueStrengthParser(Strength.SOFT))
          .put("weakValues", new ValueStrengthParser(Strength.WEAK))
          .put("recordStats", new RecordStatsParser())
          .put("expireAfterAccess", new AccessDurationParser())

    assertNull(spec.initialCapacity);
    assertNull(spec.maximumSize);
    assertNull(spec.maximumWeight);
    assertNull(spec.concurrencyLevel);
    assertNull(spec.keyStrength);
    assertEquals(Strength.SOFT, spec.valueStrength);
    assertNull(spec.writeExpirationTimeUnit);
    assertNull(spec.accessExpirationTimeUnit);
    assertCacheBuilderEquivalence(CacheBuilder.newBuilder().softValues(), CacheBuilder.from(spec));
  }

    return this;
  }

  CacheBuilderFactory withKeyStrengths(Set<Strength> keyStrengths) {
    this.keyStrengths = Sets.newLinkedHashSet(keyStrengths);
    Preconditions.checkArgument(!this.keyStrengths.contains(Strength.SOFT));
    return this;
  }

  CacheBuilderFactory withValueStrengths(Set<Strength> valueStrengths) {
    this.valueStrengths = Sets.newLinkedHashSet(valueStrengths);
    return this;
  }

          .put("concurrencyLevel", new ConcurrencyLevelParser())
          .put("weakKeys", new KeyStrengthParser(Strength.WEAK))
          .put("softValues", new ValueStrengthParser(Strength.SOFT))
          .put("weakValues", new ValueStrengthParser(Strength.WEAK))
          .put("recordStats", new RecordStatsParser())
          .put("expireAfterAccess", new AccessDurationParser())

   */
  private boolean finalizeReference(Reference<?> reference, Method finalizeReferentMethod) {
    /*
     * This is for the benefit of phantom references. Weak and soft references will have already
     * been cleared by this point.
     */
    reference.clear();

    if (reference == frqReference) {
      /*

        InternalEntry entry = map.getEntry(sample);
        if (entry != null) {
          Object canonical = entry.getKey();
          if (canonical != null) { // only matters if weak/soft keys are used
            // The compiler would know this is safe if not for our use of raw types (see above).
            @SuppressWarnings("unchecked")
            E result = (E) canonical;
            return result;

   */
  private boolean finalizeReference(Reference<?> reference, Method finalizeReferentMethod) {
    /*
     * This is for the benefit of phantom references. Weak and soft references will have already
     * been cleared by this point.
     */
    reference.clear();

    if (reference == frqReference) {
      /*

   * 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.

      if (ref != null) {
        ref.clear();
      }
    }
  }

  /**
   * Poke into the Cache internals to simulate garbage collection of the given key. This assumes
   * that the given entry is a weak or soft reference, and throws an IllegalStateException if that
   * assumption does not hold.
   */
  static <K, V> void simulateKeyReclamation(Cache<K, V> cache, K key) {
    ReferenceEntry<K, V> entry = getReferenceEntry(cache, key);

   * 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. */