https://lucene.apache.org/core/8_10_0/core/org/apache/lucene/index/UpgradeIndexMergePolicy.html
UpgradeIndexMergePolicy (Lucene 8.10.0 API)
luceneapi
https://lucene.apache.org/core/5_3_1/core/org/apache/lucene/index/UpgradeIndexMergePolicy.html
UpgradeIndexMergePolicy (Lucene 5.3.1 API)
luceneapi
https://lucene.apache.org/core/7_0_0/core/org/apache/lucene/index/class-use/UpgradeIndexMergePolicy.html
Uses of Class org.apache.lucene.index.UpgradeIndexMergePolicy (Lucene 7.0.0 API)
apache luceneusesclass