Currently the BucketingSink allows addition of part prefix, pending prefix/suffix and in-progress prefix/suffix via setter methods. Can we also support setting part suffixes?
An instance where this maybe useful: I am currently writing GZIP compressed output to S3 using the BucketingSink and I would want the uploaded files to have a ".gz" or ".zip" extensions (if the files does not have such an extensionelse they are written as garbled bytes and don't get rendered correctly for reading). I don't see a way of doing this apart from setting a part file prefix with the required file extension.  

Thanks
Lakshmi