Hi, I would like to implement a multi-field "sum" function[1], but I am not sure what would be the best way to approach it. Should I add a new method to the DataStream class or would it be better to add it to a specialized stream? Should it be based on existing operators/streams, or should I implement a new operator/stream? What do you think about this?
[1] - https://issues.apache.org/jira/browse/FLINK-4029 Best regards, Ivan.
