code: V getLiveValue(ReferenceEntry<K, V> entry) {
      if (entry.getKey() == null) {
        return null;
      }
      V value = entry.getValueReference().get();
      if (value == null) {
        return null;
      }
  
      if (expires() && isExpired(entry)) {
        return null;
      }
      return value;
    }
docs: Gets the value from an entry. Returns {@code null} if the entry is invalid,
  partially-collected, computing, or expired. Unlike {@link Segment#getLiveValue} this method
  does not attempt to clean up stale entries.