### Question:
Utils { public static void pad(StringBuilder sb, char c, int count) { for (int i = 0; i < count; ++i) { sb.append(c); } } private  Utils(); static int indexOf(T[] array, T value); static boolean contains(T[] array, T value); static void pad(StringBuilder sb, char c, int count); static void deleteQuietly(Path dir); static void moveQuietly(Path source, Path target); static String toString(InputStream is); static byte[] toByteArray(InputStream is); static List<String> readLines(Path file); static List<String> readLines(InputStream is); static float[] toFloatArray(List<? extends Number> list); static int getCurrentEpoch(Path modelDir, String modelName); static void checkParameterValues(
            PairList<String, Parameter> parameters, boolean checkGradient, Logger logger); static void checkNDArrayValues(NDArray array, Logger logger, String prefix);  }### Answer:
@Test public void testPad() { StringBuilder sb = new StringBuilder(); sb.append("Hello"); Utils.pad(sb, 'a', 5); Assert.assertEquals(sb.toString(), "Helloaaaaa"); }