https://opennlp.apache.org/docs/2.5.4/apidocs/opennlp-tools/opennlp/tools/stemmer/snowball/danishStemmer.html
danishStemmer (Apache OpenNLP Tools 2.5.4 API)
declaration: package: opennlp.tools.stemmer.snowball, class: danishStemmer
apache opennlptoolsapi
https://lucenenet.apache.org/docs/3.0.3/d6/d1d/_danish_stemmer_8cs_source.html
Lucene.Net: contrib/Snowball/SF/Snowball/Ext/DanishStemmer.cs Source File
cs sourcelucenecontribsnowballsf