This pipeline aggregation runs a script on each bucket in the parent aggregation to determine whether the bucket is kept in the final aggregation tree. If the script returns true the bucket is retained, if it returns false the bucket is dropped
This adds a new pipeline aggregation, the cumulative sum aggregation. This is a parent aggregation which must be specified as a sub-aggregation to a histogram or date_histogram aggregation. It will add a new aggregation to each bucket containing the sum of a specified metrics over this and all previous buckets.
