class not found problem with WordTokenizer

[palmafr]

Running the following code by importing the v1.28 jar from maven repo shows an error:

final FrequencyAnalyzer frequencyAnalyzer = new FrequencyAnalyzer();
final List wordFrequencies = frequencyAnalyzer.load("text/my_text_file.txt");
final Dimension dimension = new Dimension(600, 600);
final WordCloud wordCloud = new WordCloud(dimension, CollisionMode.RECTANGLE);
wordCloud.setPadding(0);
wordCloud.setBackground(new RectangleBackground(dimension));
wordCloud.setColorPalette(new ColorPalette(Color.RED, Color.GREEN, Color.YELLOW, Color.BLUE));
wordCloud.setFontScalar(new LinearFontScalar(10, 40));
wordCloud.build(wordFrequencies);
wordCloud.writeToFile("kumo-core/output/wordcloud_rectangle.png");

class not found problem with WordTokenizer

Has anyone faced the same problem?