docs: private void setBufferToCurrentChunkIfPossible() {
        ChunkCacheKey key = new ChunkCacheKey(fileKey.getIndexName(), filename, currentLoadedChunk, chunkSize, affinitySegmentId);
        buffer = (byte[]) chunksCache.get(key);
        if (buffer == null) {
           currentLoadedChunk--;
           bufferPosition = chunkSize;
        }
        else {
           currentBufferSize = buffer.length;
        }
     }