/**
 * Calculates the weights of cache entries.
 *
 * @author Charles Fry
 * @since 11.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface Weigher<K, V> {

  /**
   * Returns the weight of a cache entry. There is no unit for entry weights; rather they are simply
   * relative to each other.
   *
   * @return the weight of the entry; must be non-negative
   */

/**
 * Calculates the weights of cache entries.
 *
 * @author Charles Fry
 * @since 11.0
 */
@GwtCompatible
@FunctionalInterface
@ElementTypesAreNonnullByDefault
public interface Weigher<K, V> {

  /**
   * Returns the weight of a cache entry. There is no unit for entry weights; rather they are simply
   * relative to each other.
   *
   * @return the weight of the entry; must be non-negative
   */

      // but work beyond that must take at least one second
      assertTrue(afterBurst >= 1000);
    }
  }

  /**
   * This neat test shows that no matter what weights we use in our requests, if we push X amount of
   * permits in a cool state, where X = rate * timeToCoolDown, and we have specified a
   * timeToWarmUp() period, it will cost as the prescribed amount of time. E.g., calling

      // but work beyond that must take at least one second
      assertTrue(afterBurst >= 1000);
    }
  }

  /**
   * This neat test shows that no matter what weights we use in our requests, if we push X amount of
   * permits in a cool state, where X = rate * timeToCoolDown, and we have specified a
   * timeToWarmUp() period, it will cost as the prescribed amount of time. E.g., calling

      ValueReference<K, V> previous = entry.getValueReference();
      int weight = map.weigher.weigh(key, value);
      checkState(weight >= 0, "Weights must be non-negative");

      ValueReference<K, V> valueReference =
          map.valueStrength.referenceValue(this, entry, value, weight);
      entry.setValueReference(valueReference);
      recordWrite(entry, weight, now);
      previous.notifyNewValue(value);
    }

    checkArgument(maximumWeight >= 0, "maximum weight must not be negative");
    this.maximumWeight = maximumWeight;
    return this;
  }

  /**
   * Specifies the weigher to use in determining the weight of entries. Entry weight is taken into
   * consideration by {@link #maximumWeight(long)} when determining which entries to evict, and use

      ValueReference<K, V> previous = entry.getValueReference();
      int weight = map.weigher.weigh(key, value);
      checkState(weight >= 0, "Weights must be non-negative");

      ValueReference<K, V> valueReference =
          map.valueStrength.referenceValue(this, entry, value, weight);
      entry.setValueReference(valueReference);
      recordWrite(entry, weight, now);
      previous.notifyNewValue(value);
    }

    checkArgument(maximumWeight >= 0, "maximum weight must not be negative");
    this.maximumWeight = maximumWeight;
    return this;
  }

  /**
   * Specifies the weigher to use in determining the weight of entries. Entry weight is taken into
   * consideration by {@link #maximumWeight(long)} when determining which entries to evict, and use

      successor(this, right, succ());
      height = Math.max(2, height);
      distinctElements++;
      totalCount += count;
      return this;
    }

    private AvlNode<E> addLeftChild(@ParametricNullness E e, int count) {
      left = new AvlNode<>(e, count);
      successor(pred(), left, this);
      height = Math.max(2, height);
      distinctElements++;
      totalCount += count;

    assertThat(keySet).containsExactly(0, 1, 2, 3, 4, 5, 6, 7, 8, 9);

    // add an at-the-maximum-weight entry
    getAll(cache, asList(45));
    CacheTesting.drainRecencyQueues(cache);
    assertThat(keySet).containsExactly(0, 45);

    // add an over-the-maximum-weight entry
    getAll(cache, asList(46));
    CacheTesting.drainRecencyQueues(cache);
    assertThat(keySet).contains(0);
  }