Expert: {@link IndexWriter} uses an instance implementing this interface to execute the merges selected by a {@link MergePolicy}. The default MergeScheduler is {@link ConcurrentMergeScheduler}.

NOTE: This API is new and still experimental (subject to change suddenly in the next release)

NOTE: This class typically requires access to package-private APIs (eg, SegmentInfos) to do its job; if you implement your own MergePolicy, you'll need to put it in package Lucene.Net.Index in order to use these APIs.