List<String> d4 = tokenizer.tokenize(FLOWER_WIKI);
List<String> d5 = tokenizer.tokenize(LILIUM_WIKI);
List<String> d6 = tokenizer.tokenize(ROSE_WIKI);
List<List<String>> training = Arrays.asList(d1, d2, d4, d5);
TFIDF tfidf = new TFIDF();
// When
tfidf.init(training, 20);
// Then
// System.out.println(Arrays.toString(tfidf.extractFeatures(d3)));
// System.out.println(Arrays.toString(tfidf.extractFeatures(d6)));
assertNotNull(tfidf.extractFeatures(d3));
assertNotNull(tfidf.extractFeatures(d6));
}