public class Res { public static final Res.R<String, Object> R = new R<>() { final String param = ""; @Override public void la(String s, Object o) { System.out.println(param); } }; void bar(R r){} interface R<S, T> { void la(S s, T t); } private void validateStructuresCookie(Res cookie) { cookie.bar(<caret>R); } }