@Test
public void firstAsNullIfListEmpty() throws Exception {

    Type compositeType1 = Converter.first(TestData.class, "empty");
    assertThat(fromJson(compositeType1, "{\n"
          + "  \"empty\": null\n"
          + '}')).isNull();
    Type compositeType2 = Converter.first(TestData.class, "empty");
    assertThat(fromJson(compositeType2, "{\n"
          + "  \"empty\": []\n"
          + '}')).isNull();
}