val key = key(request.url)
    val snapshot: DiskLruCache.Snapshot =
      try {
        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()