https://lucene.apache.org/core/7_7_2/core/org/apache/lucene/util/MapOfSets.html
MapOfSets (Lucene 7.7.2 API)
luceneapi
https://lucene.apache.org/core/10_3_0/core/org/apache/lucene/util/MapOfSets.html
MapOfSets (Lucene 10.3.0 core API)
declaration: package: org.apache.lucene.util, class: MapOfSets
lucenecoreapi
https://lucene.apache.org/core/5_4_0/core/org/apache/lucene/util/MapOfSets.html
MapOfSets (Lucene 5.4.0 API)
luceneapi
https://lucene.apache.org/core/5_3_1/core/org/apache/lucene/util/MapOfSets.html
MapOfSets (Lucene 5.3.1 API)
luceneapi