Strength keyStrength() {
    return entryHelper.keyStrength();
  }

  @VisibleForTesting
  Strength valueStrength() {
    return entryHelper.valueStrength();
  }

  @VisibleForTesting
  Equivalence<Object> valueEquivalence() {
    return entryHelper.valueStrength().defaultEquivalence();
  }

  // ConcurrentMap methods

  @Override
  public boolean isEmpty() {
    /*

  }

  private static void checkStrength(
      LocalCache<Object, Object> map, Strength keyStrength, Strength valueStrength) {
    assertSame(keyStrength, map.keyStrength);
    assertSame(valueStrength, map.valueStrength);
    assertSame(keyStrength.defaultEquivalence(), map.keyEquivalence);
    assertSame(valueStrength.defaultEquivalence(), map.valueEquivalence);
  }

  public void testSetExpireAfterWrite() {

  }

  private static void checkStrength(
      LocalCache<Object, Object> map, Strength keyStrength, Strength valueStrength) {
    assertSame(keyStrength, map.keyStrength);
    assertSame(valueStrength, map.valueStrength);
    assertSame(keyStrength.defaultEquivalence(), map.keyEquivalence);
    assertSame(valueStrength.defaultEquivalence(), map.valueEquivalence);
  }

  public void testSetExpireAfterWrite() {