/**
 * 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
   */

    @Override
    public int weigh(Object key, Object value) {
      return constant;
    }
  }

  static final class IntKeyWeigher implements Weigher<Integer, Object> {
    @Override
    public int weigh(Integer key, Object value) {
      return key;
    }
  }

  static final class IntValueWeigher implements Weigher<Object, Integer> {
    @Override
    public int weigh(Object key, Integer value) {
      return value;
    }

    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);
  }

    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);
  }

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

  /**
   * Specifies the maximum weight of entries the cache may contain. Weight is determined using the
   * {@link Weigher} specified with {@link #weigher}, and use of this method requires a

          spec.maximumWeight == null, "maximum weight was already set to %s", spec.maximumWeight);
      spec.maximumSize = value;
    }
  }

  /** Parse maximumWeight */
  static class MaximumWeightParser extends LongParser {
    @Override
    protected void parseLong(CacheBuilderSpec spec, long value) {
      checkArgument(
          spec.maximumWeight == null, "maximum weight was already set to %s", spec.maximumWeight);

    @Override
    public int weigh(Object key, Object value) {
      return constant;
    }
  }

  static final class IntKeyWeigher implements Weigher<Integer, Object> {
    @Override
    public int weigh(Integer key, Object value) {
      return key;
    }
  }

  static final class IntValueWeigher implements Weigher<Object, Integer> {
    @Override
    public int weigh(Object key, Integer value) {
      return value;
    }

/**
 * 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
   */

      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);
    }

          spec.maximumWeight == null, "maximum weight was already set to %s", spec.maximumWeight);
      spec.maximumSize = value;
    }
  }

  /** Parse maximumWeight */
  static class MaximumWeightParser extends LongParser {
    @Override
    protected void parseLong(CacheBuilderSpec spec, long value) {
      checkArgument(
          spec.maximumWeight == null, "maximum weight was already set to %s", spec.maximumWeight);