VersionGC uses way too much memory if there is a large pile of garbage

It has been noticed that on a system where revision-gc (VersionGarbageCollector of mongomk) did not run for a few days (due to not interfering with some tests/large bulk operations) that there was such a large pile of garbage accumulating, that the following code

VersionGarbageCollector.collectDeletedDocuments

in the for loop, creates such a large list of NodeDocuments to delete (docIdsToDelete) that it uses up too much memory, causing the JVM's GC to constantly spin in Full-GCs.