@Test
public void testClusteringWithDfThreshold() {

  STCClusteringAlgorithm algorithm = algorithm();
  algorithm.preprocessing.wordDfThreshold.set(20);
  List<Cluster<Document>> clusters =
      algorithm.cluster(
          SampleDocumentData.DOCUMENTS_DATA_MINING.stream(),
          CachedLangComponents.loadCached("English"));
  Assertions.assertThat(clusters.size()).isEqualTo(0);
}