List<StoreKey> getSuccessfullyPutChunkIds() {
      return indexToChunkIdsAndChunkSizes.values().stream().map(Pair::getFirst).collect(Collectors.toList());
    }
@return a list of all of the successfully put chunk ids associated with this blob
ambry-router/src/main/java/com/github/ambry/router/PutOperation.java