final CreateIndexResponse indexResponse = client.admin()
                    .indices()
                    .prepareCreate(indexName)
                    .setSource(source, XContentType.JSON)
                    .execute()
                    .actionGet(fessConfig.getIndexIndicesTimeout());
            if (indexResponse.isAcknowledged()) {

        cache[key] ?: return null
      } catch (_: IOException) {
        return null // Give up because the cache cannot be read.
      }

    val entry: Entry =
      try {
        Entry(snapshot.getSource(ENTRY_METADATA))
      } catch (_: IOException) {
        snapshot.closeQuietly()
        return null
      }

    val response = entry.response(snapshot)
    if (!entry.matches(request, response)) {