### Question:
NonEmptyStringAnnotationFormatterFactory implements
        AnnotationFormatterFactory<NonEmpty> { @Override public final Set<Class<?>> getFieldTypes() { return this.fieldTypes; } NonEmptyStringAnnotationFormatterFactory(); @Override final Set<Class<?>> getFieldTypes(); @Override Printer<String> getPrinter(NonEmpty annotation, Class<?> fieldType); @Override Parser<String> getParser(NonEmpty annotation, Class<?> fieldType);  }### Answer:
@Test public void testGetFieldTypes() { final Set<Class<?>> fieldTypes = testee.getFieldTypes(); assertThat(fieldTypes).hasSize(1).contains(String.class); }