### Question:
ObjectFieldActions implements AtlasFieldAction { @AtlasActionProcessor public static Boolean isNull(IsNull action, Object input) { return input == null; }  @AtlasActionProcessor static Integer count(Count action, List<Object> inputs); @AtlasActionProcessor static Boolean contains(Contains contains, List<Object> inputs); @AtlasActionProcessor static Boolean equals(Equals equals, Object input); @AtlasActionProcessor static Boolean isNull(IsNull action, Object input); @AtlasActionProcessor static Object itemAt(ItemAt itemAt, List<Object> inputs); @AtlasActionProcessor static Integer length(Length length, Object input);  }### Answer:
@Test public void testIsNull() { assertTrue(ObjectFieldActions.isNull(null, null)); assertFalse(ObjectFieldActions.isNull(null, "")); assertFalse(ObjectFieldActions.isNull(null, new Object[0])); }