.build();
    cache.put(1, 2);

    // explicitly remove the existing value
    cache.asMap().computeIfPresent(1, (key, value) -> null);
    assertThat(notifications).hasSize(1);
    CacheTesting.checkEmpty(cache);

    // ensure no zombie entry remains
    cache.asMap().computeIfPresent(1, (key, value) -> null);
    assertThat(notifications).hasSize(1);
    CacheTesting.checkEmpty(cache);
  }

        // use original key
        return parent.computeIfAbsent(key, mappingFunction);
    }

    @Override
    public V computeIfPresent(final K key, final BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
        // use original key
        return parent.computeIfPresent(key, remappingFunction);
    }

    @Override