### Question:
NullPadder implements Padder { public String pad(String data, int maxLength) { return data; }  String pad(String data, int maxLength); String unpad(String paddedData); static final NullPadder INSTANCE; }### Answer:
@Test public void testPad() throws Throwable { String result = NullPadder.INSTANCE.pad("testNullPadderData", 100); assertEquals("testNullPadderData", result, "result"); }
@Test public void testPad1() throws Throwable { String result = new NullPadder().pad(null, 100); assertNull(result, "result"); }