### Question:
TextUtil { public static void appendNullByte(Text text) { text.append(nullByte, 0, nullByte.length); }  static void textAppend(Text text, String string); static void textAppend(Text text, String string, boolean replaceBadChar); static void textAppend(Text t, long s); static void appendNullByte(Text text); static void textAppendNoNull(Text t, String s); static void textAppendNoNull(Text t, String s, boolean replaceBadChar); static byte[] toUtf8(String string); static String fromUtf8(byte[] bytes);  }### Answer:
@Test public void testAppendNullByte() { Text text = new Text(new byte[] {1, 2, 3}); TextUtil.appendNullByte(text); Assert.assertEquals(4, text.getLength()); Assert.assertEquals(0, text.getBytes()[3]); }