public static FormValidation validateRequired(String value) {
        if (Util.fixEmptyAndTrim(value) == null)
            return error(Messages.FormValidation_ValidateRequired());
        return ok();
    }
@Test
    public void testValidateRequired_Null() {
        FormValidation actual = FormValidation.validateRequired(null);
        assertNotNull(actual);
        assertEquals(FormValidation.Kind.ERROR, actual.kind);
    }