In Scala RDD, we have:

import io.archivesunleashed._
import io.archivesunleashed.matchbox._

RecordLoader.loadArchives("src/test/resources/warc/example.warc.gz", sc).keepValidPages()
  .map(r => ExtractDomain(r.getUrl))
  .countItems()
  .take(10)

In Scala DF, we have:

import io.archivesunleashed._
import io.archivesunleashed.df._

RecordLoader.loadArchives("src/test/resources/warc/example.warc.gz", sc).extractValidPagesDF()
  .select(ExtractBaseDomain($"Url").as("Domain"))
  .groupBy("Domain").count().orderBy(desc("count"))
  .show(20, False)

We should be consistent: ExtractDomain or ExtractBaseDomain?