Client.java

List<Object> nested = new ArrayList<Object>();
nested.addAll(someNesteditems);
nested.addAll(someOtherNestedItems);

SampleResource resource = new SampleResource();
resource.nested = new Resources<Object>(nested);

SampleResource.java

@JsonAutoDetect(fieldVisibility = Visibility.ANY)
private static class SampleResource extends ResourceSupport {

	@JsonUnwrapped Resources<Object> nested;
}