### Question:
AdapterUtils { public static String withoutDecimals(String s) { Objects.requireNonNull(s); int dotIndex = s.lastIndexOf("."); return dotIndex == -1 ? s : s.substring(0, dotIndex); } private  AdapterUtils(); static Boolean parseBoolean(String s); static Date parseDate(String s); static LocalDate parseLocalDate(String s); static LocalDateTime parseLocalDateTime(String s); static String withoutDecimals(String s); static Enum<?> findEnumIgnoreCase(Class<? extends Enum<?>> enumType, String name); static Class<?> uncheckedClassForName(String s);  }### Answer:
@Test public void testRemoveDecimals100ShouldLeaveIntact() throws Exception { assertEquals("100", AdapterUtils.withoutDecimals("100")); }
@Test public void testRemoveDecimals100_0ShouldRemoveDecimals() throws Exception { assertEquals("100", AdapterUtils.withoutDecimals("100")); }
@Test public void testRemoveDecimals100_123ShouldRemoveDecimals() throws Exception { assertEquals("100", AdapterUtils.withoutDecimals("100.123")); }
@Test public void testRemoveDecimalsABCS_123ShouldRemoveDecimals() throws Exception { assertEquals("ABC", AdapterUtils.withoutDecimals("ABC.123")); }
@Test(expected = NullPointerException.class) public void testRemoveDecimalsNullInputShouldThrowException() throws Exception { AdapterUtils.withoutDecimals(null); }