DescriptionUtils { public static String createNominalDescription(Collection<String> values) { StringBuilder buffer = new StringBuilder(); int ind = 0; for (String value : values) { buffer.append(value); if (++ind < values.size()) { buffer.append(','); } } return buffer.toString(); } private  DescriptionUtils(); static String createNumericalDescription(double min, double max); static String createNominalDescription(Collection<String> values); static double[] extractNumericalRange(String description); static void extractNominalValues(String description,
                                          Collection<String> target);  }
@Test public void testCreateNominalDescription() { List<String> values = Arrays.asList("val1", "val2", "val3"); String description = DescriptionUtils.createNominalDescription(values); assertEquals("val1,val2,val3", description); }