@Test
  void emptyValueOf_considersRawType() throws Exception {
    Type listStringType = LastTypeParameter.class.getDeclaredField("LIST_STRING").getGenericType();
    assertThat((List<?>) Util.emptyValueOf(listStringType)).isEmpty();
  }
In other words, {@code List<String>} is as empty as {@code List<?>}.
core/src/test/java/feign/UtilTest.java