merge

open override fun merge(record: Record, cacheHeaders: CacheHeaders): Set<String>
open override fun merge(records: Collection<Record>, cacheHeaders: CacheHeaders): Set<String>
open override fun merge(    record: Record,     cacheHeaders: CacheHeaders,     recordMerger: RecordMerger): Set<String>
open override fun merge(    records: Collection<Record>,     cacheHeaders: CacheHeaders,     recordMerger: RecordMerger): Set<String>