public static TextSingleFormField.Builder textSingleBuilder(String fieldName) {
        return new TextSingleFormField.Builder(fieldName, Type.text_single);
    }
@Test
    public void testThrowExceptionWhenNullLabel() {
        TextSingleFormField.Builder builder = FormField.textSingleBuilder("type");
        assertThrows(IllegalArgumentException.class, () -> builder.setLabel(null));
    }