@Test
public void testOptionalInteger() {

    TypeLiteral<List<Integer>> listOfIntegerTypeLiteral = new TypeLiteral<List<Integer>>() {
    };
    ConversionContext context = new ConversionContext.Builder("testOptionalInteger", listOfIntegerTypeLiteral)
            .setConfiguration(Configuration.current())
            .build();
    final Optional<Integer> result = new OptionalConverter().convert("11", context);
    assertThat(result).isNotNull();
    assertThat(result.isPresent()).isTrue();
    assertThat(result.get().intValue()).isEqualTo(11);
}