void addChunkId(StoreKey storeKey, long chunkSize, int chunkIndex) {
      indexToChunkIdsAndChunkSizes.put(chunkIndex, new Pair<>(storeKey, chunkSize));
    }
Add the given blobId of a successfully put data chunk to the metadata at its position in the overall blob.
@param storeKey the blobId of the associated data chunk
@param chunkSize size of the data chunk
@param chunkIndex the position of the associated data chunk in the overall blob.
ambry-router/src/main/java/com/github/ambry/router/PutOperation.java