assertSame(Strength.STRONG, map.keyStrength);
    assertSame(Strength.STRONG, map.valueStrength);
    assertSame(map.keyStrength.defaultEquivalence(), map.keyEquivalence);
    assertSame(map.valueStrength.defaultEquivalence(), map.valueEquivalence);

    assertEquals(0, map.expireAfterAccessNanos);
    assertEquals(0, map.expireAfterWriteNanos);
    assertEquals(0, map.refreshNanos);

    assertSame(Strength.STRONG, map.keyStrength);
    assertSame(Strength.STRONG, map.valueStrength);
    assertSame(map.keyStrength.defaultEquivalence(), map.keyEquivalence);
    assertSame(map.valueStrength.defaultEquivalence(), map.valueEquivalence);

    assertEquals(0, map.expireAfterAccessNanos);
    assertEquals(0, map.expireAfterWriteNanos);
    assertEquals(0, map.refreshNanos);

    }
    throw new AssertionError();
  }

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

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

    /**

    }
    throw new AssertionError();
  }

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

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

    /**

    keyEquivalence = checkNotNull(equivalence);
    return this;
  }

  Equivalence<Object> getKeyEquivalence() {
    return MoreObjects.firstNonNull(keyEquivalence, getKeyStrength().defaultEquivalence());
  }

  /**
   * Sets a custom {@code Equivalence} strategy for comparing values.
   *
   * <p>By default, the cache uses {@link Equivalence#identity} to determine value equality when

    keyEquivalence = checkNotNull(equivalence);
    return this;
  }

  Equivalence<Object> getKeyEquivalence() {
    return MoreObjects.firstNonNull(keyEquivalence, getKeyStrength().defaultEquivalence());
  }

  /**
   * Sets a custom {@code Equivalence} strategy for comparing values.
   *
   * <p>By default, the cache uses {@link Equivalence#identity} to determine value equality when

        return (weight == 1)
            ? new StrongValueReference<K, V>(value)
            : new WeightedStrongValueReference<K, V>(value, weight);
      }

      @Override
      Equivalence<Object> defaultEquivalence() {
        return Equivalence.equals();
      }
    },
    SOFT {
      @Override
      <K, V> ValueReference<K, V> referenceValue(